diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e4d44cc..ae6bc99 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -203,9 +203,9 @@ jobs:
           if-no-files-found: error
           retention-days: 30
           path: |
-            build/libs/SkysTerrainSmoother-0.1.0.2603001.jar
-            build/libs/SkysTerrainSmoother-0.1.0.2603001-sources.jar
-            build/libs/SkysTerrainSmoother-0.1.0.2603001-javadoc.jar
+            build/libs/SkysTerrainSmoother-0.1.1.2603001.jar
+            build/libs/SkysTerrainSmoother-0.1.1.2603001-sources.jar
+            build/libs/SkysTerrainSmoother-0.1.1.2603001-javadoc.jar
             build/release/SHA256SUMS
             CHANGELOG.md
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 28ea402..f0ca1a8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.1.1.2603001
+
+- Gentle surface terraces use full-width slabs at smoothing levels 2 and 3, giving each rise a wider tread.
+
 ## 0.1.0.2603001
 
 - Updated Terrain Smoother for Minecraft 26.3 on Forge.
diff --git a/README.md b/README.md
index bc8008b..643b862 100644
--- a/README.md
+++ b/README.md
@@ -14,8 +14,10 @@ Set `worldgen.smoothingLevel` in `config/skysterrainsmoother-common.toml`:
 3. **Slabs, steps and corners** - also uses pieces covering a quarter of a
    slab's footprint.
 
-Every smoothing piece is half a block tall. If a material doesn't have steps
-or corners, it uses its slab at higher levels wherever a slab fits safely.
+Every smoothing piece is half a block tall. Gentle surface terraces use a
+full-width slab when there is room on both sides of a one-block rise. If a
+material doesn't have steps or corners, it uses its slab at higher levels
+wherever a slab fits safely.
 
 Narrow mountain ledges keep their downhill edge at its original height, rather
 than gaining a row of slabs that recreates a full-block step. Wider terraces
@@ -52,7 +54,7 @@ For **Minecraft 26.3**, use **Forge 66.0.2** and **Java 25**, with:
 
 - Sky's Grass Slabs **1.2.0.2603001**.
 - Sky's Building Pieces **0.3.9.2603001**.
-- Sky's Terrain Smoother **0.1.0.2603001**.
+- Sky's Terrain Smoother **0.1.1.2603001**.
 
 Install all three main jars on both the client and server.
 
diff --git a/build.gradle b/build.gradle
index fdf265a..abd1a2f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -760,6 +760,11 @@ eclipse {
         downloadSources = true
         downloadJavadoc = true
         file.whenMerged { classpath ->
+            // Forge supplies MixinExtras at launch. Its common jar is only needed for compilation.
+            classpath.entries.removeAll { entry ->
+                entry instanceof org.gradle.plugins.ide.eclipse.model.Library &&
+                        file(entry.path).name.startsWith('mixinextras-common-')
+            }
             // Eclipse copies these files on every build. Use Gradle's expanded metadata, never the template.
             def resources = classpath.entries.findAll {
                 it instanceof org.gradle.plugins.ide.eclipse.model.SourceFolder &&
@@ -889,6 +894,12 @@ tasks.register('verifyEclipseProductionClasspath') {
         }
         File metadata = file('bin/main/META-INF/mods.toml')
         def eclipseClasspath = new groovy.xml.XmlSlurper().parse(file('.classpath'))
+        def mixinExtrasLibraries = eclipseClasspath.classpathentry.findAll {
+            it.@kind == 'lib' && file(it.@path.text()).name.startsWith('mixinextras-')
+        }.collect { file(it.@path.text()).name }
+        if (mixinExtrasLibraries.size() != 1 || !mixinExtrasLibraries.first().startsWith('mixinextras-forge-')) {
+            throw new GradleException('Eclipse must use the MixinExtras runtime supplied by Forge')
+        }
         def piecesLibraries = eclipseClasspath.classpathentry.findAll {
             it.@kind == 'lib' && it.@path.text().tokenize('/\\').last().startsWith('SkysBuildingPieces-')
         }*.@path*.text().collect { file(it).canonicalFile }
diff --git a/gradle.properties b/gradle.properties
index 650777b..cc6edb3 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -24,7 +24,7 @@ release_enabled=true
 curseforge_project_id=1768953
 mod_name=Sky's Terrain Smoother
 mod_license=LGPL-2.1-only
-mod_version=0.1.0.2603001
+mod_version=0.1.1.2603001
 mod_group=zone.moddev.mc.skysterrainsmoother
 mod_authors=SkyBlade1978
 mod_description=Smooths new Overworld surfaces with existing slabs, steps and corners. Optional Mineralogy support.
diff --git a/gradle/development-log4j2.xml b/gradle/development-log4j2.xml
index 1281087..4fe80ca 100644
--- a/gradle/development-log4j2.xml
+++ b/gradle/development-log4j2.xml
@@ -4,7 +4,8 @@
     <Console name="Console" target="SYSTEM_OUT">
       <PatternLayout pattern="[%d{HH:mm:ss}] [%t/%level] [%logger]: %msg%n"/>
     </Console>
-    <File name="DevelopmentLog" fileName="logs/latest.log" append="false">
+    <!-- Forge opens latest.log when it takes over logging from bootstrap. -->
+    <File name="DevelopmentLog" fileName="logs/development-bootstrap.log" append="false">
       <PatternLayout pattern="[%d{HH:mm:ss}] [%t/%level] [%logger]: %msg%n"/>
     </File>
   </Appenders>
diff --git a/src/integrationTest/java/zone/moddev/mc/skysterrainsmoother/probe/TransitionProbe.java b/src/integrationTest/java/zone/moddev/mc/skysterrainsmoother/probe/TransitionProbe.java
index e8e37f3..2114e9f 100644
--- a/src/integrationTest/java/zone/moddev/mc/skysterrainsmoother/probe/TransitionProbe.java
+++ b/src/integrationTest/java/zone/moddev/mc/skysterrainsmoother/probe/TransitionProbe.java
@@ -38,6 +38,12 @@ static int run(ServerLevel world) {
                         BlockPos upperCap = origin.relative(uphill).above(2);
                         RuntimeProbe.require(MaterialCatalogue.instance().piece(world.getBlockState(lowCap)) == material,
                                 "the foot of a steep slope still receives its matching transition");
+                        BlockState step = material.step(direction(uphill));
+                        if (level >= 2 && step != null) {
+                            RuntimeProbe.require(world.getBlockState(lowCap).equals(step),
+                                    "the foot of consecutive rises keeps its uphill step");
+                            checks++;
+                        }
                         requireOpenDownhillEdge(world, upperCap, uphill.getOpposite(),
                                 "consecutive mountain ledges, level " + level + " / " + uphill);
                         RuntimeProbe.require(world.getChunkSource().getLoadedChunksCount() == loadedBefore,
@@ -48,9 +54,11 @@ static int run(ServerLevel world) {
 
                         prepare(world, origin, uphill, source, true, roofed);
                         SkysTerrainSmoother.engine.smooth(world, owner, level);
-                        RuntimeProbe.require(MaterialCatalogue.instance()
-                                .piece(world.getBlockState(origin.relative(uphill).above())) == material,
-                                "the bottom of a wider terrace is smoothed");
+                        BlockPos terraceCap = origin.relative(uphill).above();
+                        BlockState expected = roofed && level >= 2 && step != null ? step : material.slab;
+                        RuntimeProbe.require(world.getBlockState(terraceCap).equals(expected),
+                                "gentle surface terraces use a slab and cave terraces keep their existing shape: "
+                                        + source + " / " + uphill + " / level " + level + " / roofed " + roofed);
                         RuntimeProbe.require(MaterialCatalogue.instance()
                                 .piece(world.getBlockState(origin.relative(uphill, 3).above(2))) == material,
                                 "a wider upper terrace retains room for its own transition");
@@ -75,7 +83,7 @@ static int run(ServerLevel world) {
             checks += 2;
         }
 
-        checks += borders(world) + lateLowerFloor(world, origin);
+        checks += borders(world) + gentleBorders(world) + lateLowerFloor(world, origin);
         zone.moddev.mc.skysterrainsmoother.SkysTerrainSmoother.logger.info("TERRAIN_SMOOTHER_TRANSITIONS_PASS checks=" + checks);
         return checks;
     }
@@ -117,6 +125,40 @@ private static int borders(ServerLevel world) {
         return checks;
     }
 
+    private static int gentleBorders(ServerLevel world) {
+        TerrainMaterial material = MaterialCatalogue.instance().source(Blocks.STONE.defaultBlockState());
+        int checks = 0;
+        for (Direction uphill : new Direction[] { Direction.EAST, Direction.SOUTH }) {
+            BlockPos origin = uphill == Direction.EAST ? new BlockPos(3614, 210, 3656)
+                    : new BlockPos(3656, 210, 3614);
+            BlockPos low = origin.relative(uphill);
+            LevelChunk lowerOwner = world.getChunkAt(low);
+            LevelChunk upperOwner = world.getChunkAt(low.relative(uphill));
+            for (boolean reverse : new boolean[] { false, true }) {
+                prepare(world, origin, uphill, Blocks.STONE.defaultBlockState(), true, false);
+                int loadedBefore = world.getChunkSource().getLoadedChunksCount();
+                SkysTerrainSmoother.engine.smooth(world, reverse ? upperOwner : lowerOwner, 3);
+                SkysTerrainSmoother.engine.smooth(world, reverse ? lowerOwner : upperOwner, 3);
+                RuntimeProbe.require(world.getBlockState(low.above()).equals(material.slab),
+                        "the same gentle slab fits in both chunk orders: " + uphill);
+                RuntimeProbe.require(world.getChunkSource().getLoadedChunksCount() == loadedBefore,
+                        "terrace lookahead never loads a chunk");
+                checks += 2;
+            }
+        }
+        return checks;
+    }
+
+    private static int direction(Direction uphill) {
+        return switch (uphill) {
+            case NORTH -> 0;
+            case EAST -> 1;
+            case SOUTH -> 2;
+            case WEST -> 3;
+            default -> throw new IllegalArgumentException("Expected horizontal uphill direction");
+        };
+    }
+
     private static int lateLowerFloor(ServerLevel world, BlockPos origin) {
         LevelChunk owner = world.getChunkAt(origin);
         int checks = 0;
diff --git a/src/main/java/zone/moddev/mc/skysterrainsmoother/SkysTerrainSmoother.java b/src/main/java/zone/moddev/mc/skysterrainsmoother/SkysTerrainSmoother.java
index 2df59e2..a571e47 100644
--- a/src/main/java/zone/moddev/mc/skysterrainsmoother/SkysTerrainSmoother.java
+++ b/src/main/java/zone/moddev/mc/skysterrainsmoother/SkysTerrainSmoother.java
@@ -29,7 +29,7 @@
 public final class SkysTerrainSmoother {
     public static final String ID = "skysterrainsmoother";
     public static final String NAME = "Sky's Terrain Smoother";
-    public static final String VERSION = "0.1.0.2603001";
+    public static final String VERSION = "0.1.1.2603001";
     public static final Logger logger = LogManager.getLogger();
     public static final SmoothingEngine engine = new SmoothingEngine(MaterialCatalogue.instance());
     public static boolean enabled = true;
diff --git a/src/main/java/zone/moddev/mc/skysterrainsmoother/internal/SmoothingEngine.java b/src/main/java/zone/moddev/mc/skysterrainsmoother/internal/SmoothingEngine.java
index 2bf5eb3..10f8bba 100644
--- a/src/main/java/zone/moddev/mc/skysterrainsmoother/internal/SmoothingEngine.java
+++ b/src/main/java/zone/moddev/mc/skysterrainsmoother/internal/SmoothingEngine.java
@@ -244,8 +244,8 @@ private boolean validate(LevelAccessor world, int chunkX, int chunkZ, List<Featu
                         }
                     }
 
-                    result = transitionResult(world, placement.pos.below(), replacement,
-                            Footprint.mask(cardinal, diagonal, placement.level), placement.level);
+                    result = transitionResult(world, owner, placement.pos.below(), replacement,
+                            cardinal, diagonal, placement.level, placement.cave);
                 }
 
                 repairs.put(placement, result == null ? Blocks.AIR.defaultBlockState() : result);
@@ -397,8 +397,8 @@ private int smooth(LevelAccessor world, ChunkAccess owner, int level, boolean af
                         }
                     }
 
-                    BlockState result = transitionResult(world, support, material,
-                            Footprint.mask(cardinal, diagonal, level), level);
+                    BlockState result = transitionResult(world, owner, support, material,
+                            cardinal, diagonal, level, cave);
 
                     if (result != null) {
                         buffer.add(localBlockX | localBlockZ << 4 | (floorY + 1) << 8, result, material, cave, above);
@@ -477,13 +477,36 @@ private static boolean sameState(BlockState first, BlockState second) {
         return first.equals(second);
     }
 
-    private BlockState transitionResult(LevelAccessor world, BlockPos support, TerrainMaterial material, int mask, int level) {
+    private BlockState transitionResult(LevelAccessor world, ChunkAccess owner, BlockPos support,
+            TerrainMaterial material, int cardinal, int diagonal, int level, boolean cave) {
+        int mask = Footprint.mask(cardinal, diagonal, level);
+        if (mask == 0) {
+            return null;
+        }
+
         int lowerEdges = lowerEdges(world, support);
         int safeMask = Footprint.trimDownhillEdges(mask, lowerEdges);
         BlockState result = catalogue.result(material, safeMask, level);
 
-        // Missing finer shapes fall back to slabs. Check the real result, not just the requested footprint.
-        return result != null && (touchingEdges(result) & lowerEdges) == 0 ? result : null;
+        // Missing finer shapes fall back to slabs. Check the actual piece against the downhill edges.
+        if (result == null || (touchingEdges(result) & lowerEdges) != 0) {
+            return null;
+        }
+
+        if (!cave && level >= 2 && lowerEdges == 0 && result != material.slab && Integer.bitCount(cardinal) == 1) {
+            int uphill = Integer.numberOfTrailingZeros(cardinal);
+            if (safeMask == Footprint.EDGES[uphill]) {
+                // A full slab gives a broader tread where both sides of a one-block rise have room.
+                int dx = DX[uphill];
+                int dz = DZ[uphill];
+                if (hasTerrainFloor(world, owner, support.offset(-dx, 0, -dz))
+                        && hasTerrainFloor(world, owner, support.offset(2 * dx, 1, 2 * dz))) {
+                    return material.slab;
+                }
+            }
+        }
+
+        return result;
     }
 
     private static BlockState supportAfterPlacement(TerrainMaterial material, BlockState piece) {
@@ -586,14 +609,19 @@ private boolean higher(LevelAccessor world, ChunkAccess owner, int localX, int l
         int worldX = (owner.getPos().x() << 4) + localX;
         int worldZ = (owner.getPos().z() << 4) + localZ;
 
-        ChunkAccess neighbour = loaded(world, worldX >> 4, worldZ >> 4);
+        return hasTerrainFloor(world, owner, new BlockPos(worldX, lowerY + 1, worldZ));
+    }
 
+    private boolean hasTerrainFloor(LevelAccessor world, ChunkAccess owner, BlockPos floor) {
+        int chunkX = floor.getX() >> 4;
+        int chunkZ = floor.getZ() >> 4;
+        ChunkAccess neighbour = chunkX == owner.getPos().x() && chunkZ == owner.getPos().z()
+                ? owner : loaded(world, chunkX, chunkZ);
         if (neighbour == null) {
             return false;
         }
 
-        // Compare logical floors at this height, including existing caps over BOP's native soil.
-        BlockPos floor = new BlockPos(worldX, lowerY + 1, worldZ);
+        // Read the same logical height before and after a neighbouring column is capped.
         BlockState state = neighbour.getBlockState(floor);
         BlockState above = neighbour.getBlockState(floor.above());
 
@@ -601,8 +629,7 @@ private boolean higher(LevelAccessor world, ChunkAccess owner, int localX, int l
         TerrainMaterial cap = catalogue.piece(above);
 
         if (cap != null) {
-            return source != null || catalogue.source(state) == cap
-                    || cap.supportAfterPlacement != null && state.equals(cap.supportAfterPlacement)
+            return source != null || cap.supportAfterPlacement != null && state.equals(cap.supportAfterPlacement)
                     || oreSupport(state);
         }
 
diff --git a/src/test/java/zone/moddev/mc/skysterrainsmoother/ProjectContractTest.java b/src/test/java/zone/moddev/mc/skysterrainsmoother/ProjectContractTest.java
index 9f40efe..99216ce 100644
--- a/src/test/java/zone/moddev/mc/skysterrainsmoother/ProjectContractTest.java
+++ b/src/test/java/zone/moddev/mc/skysterrainsmoother/ProjectContractTest.java
@@ -15,7 +15,7 @@ class ProjectContractTest {
     void targetMetadataAndToolchainMatchTheNativeRuntime() throws Exception {
         Properties metadata = new Properties();
         metadata.load(new java.io.StringReader(text(Paths.get("gradle.properties"))));
-        assertEquals("0.1.0.2603001", metadata.getProperty("mod_version"));
+        assertEquals("0.1.1.2603001", metadata.getProperty("mod_version"));
         assertEquals(metadata.getProperty("mod_version"), SkysTerrainSmoother.VERSION);
         assertEquals("26.3", metadata.getProperty("minecraft_version"));
         assertEquals("66.0.2", metadata.getProperty("forge_version"));