diff --git a/src/functionalTest/java/codechicken/multipart/test/PartConverterFunctionalTest.java b/src/functionalTest/java/codechicken/multipart/test/PartConverterFunctionalTest.java
new file mode 100644
index 0000000..ef6bb65
--- /dev/null
+++ b/src/functionalTest/java/codechicken/multipart/test/PartConverterFunctionalTest.java
@@ -0,0 +1,118 @@
+package codechicken.multipart.test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotSame;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import net.minecraft.block.Block;
+import net.minecraft.init.Blocks;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.tileentity.TileEntity;
+import net.minecraft.world.World;
+
+import org.junit.jupiter.api.Test;
+
+import codechicken.lib.vec.BlockCoord;
+import codechicken.multipart.MultiPartRegistry;
+import codechicken.multipart.MultiPartRegistry.IPartConverter;
+import codechicken.multipart.TMultiPart;
+import codechicken.multipart.TileMultipart;
+
+class PartConverterFunctionalTest {
+
+    @Test
+    void probesLeaveOriginalTileIntactAndCommitRunsConversionHooksInOrder() {
+        World world = MinecraftServer.getServer().worldServers[0];
+        BlockCoord pos = new BlockCoord(58, 200, 48);
+        world.getChunkFromBlockCoords(pos.x, pos.z);
+        world.setBlock(pos.x, pos.y, pos.z, Blocks.chest, 0, 0);
+        TileEntity original = world.getTileEntity(pos.x, pos.y, pos.z);
+        List<String> events = new ArrayList<>();
+        List<TMultiPart> attempts = new ArrayList<>();
+        MultiPartRegistry.registerConverter(new IPartConverter() {
+
+            @Override
+            public Iterable<Block> blockTypes() {
+                return Collections.singletonList(Blocks.chest);
+            }
+
+            @Override
+            public TMultiPart convert(World supplied, BlockCoord location) {
+                if (supplied != world || !pos.equals(location)) return null;
+                assertSame(original, world.getTileEntity(pos.x, pos.y, pos.z));
+                TMultiPart part = new MultipartGeneratorFunctionalTest.PlainPart() {
+
+                    @Override
+                    public void invalidateConvertedTile() {
+                        assertSame(original, world.getTileEntity(pos.x, pos.y, pos.z));
+                        assertSame(Blocks.chest, world.getBlock(pos.x, pos.y, pos.z));
+                        events.add("invalidate");
+                    }
+
+                    @Override
+                    public void onConverted() {
+                        assertSame(tile(), world.getTileEntity(pos.x, pos.y, pos.z));
+                        assertTrue(original.isInvalid());
+                        events.add("converted");
+                        super.onConverted();
+                    }
+
+                    @Override
+                    public void onAdded() {
+                        events.add("converted-added");
+                        super.onAdded();
+                    }
+                };
+                attempts.add(part);
+                return part;
+            }
+        });
+        try {
+            TMultiPart direct = MultiPartRegistry.convertBlock(world, pos, Blocks.chest);
+            assertNull(direct.tile());
+            TMultiPart rejected = new MultipartGeneratorFunctionalTest.PlainPart() {
+
+                @Override
+                public boolean occlusionTest(TMultiPart other) {
+                    return false;
+                }
+            };
+            assertFalse(TileMultipart.canPlacePart(world, pos, rejected));
+            TMultiPart added = new MultipartGeneratorFunctionalTest.PlainPart() {
+
+                @Override
+                public void onAdded() {
+                    events.add("new-added");
+                    super.onAdded();
+                }
+            };
+            assertTrue(TileMultipart.canPlacePart(world, pos, added));
+            assertEquals(3, attempts.size());
+            assertTrue(events.isEmpty());
+            assertSame(original, world.getTileEntity(pos.x, pos.y, pos.z));
+            assertFalse(original.isInvalid());
+            assertNull(added.tile());
+            TileMultipart installed = TileMultipart.addPart(world, pos, added);
+            assertEquals(4, attempts.size());
+            assertEquals(Arrays.asList("invalidate", "converted", "converted-added", "new-added"), events);
+            assertSame(installed, world.getTileEntity(pos.x, pos.y, pos.z));
+            assertSame(attempts.get(3), installed.jPartList().get(0));
+            assertSame(added, installed.jPartList().get(1));
+            for (int i = 0; i < 3; i++) {
+                assertNotSame(attempts.get(i), attempts.get(3));
+            }
+            assertSame(installed, TileMultipart.getOrConvertTile(world, pos));
+            assertEquals(4, attempts.size(), "An installed tile bypasses converters");
+        } finally {
+            world.setBlockToAir(pos.x, pos.y, pos.z);
+        }
+    }
+}
diff --git a/src/test/java/codechicken/multipart/MultiPartRegistryCharacterizationTest.java b/src/test/java/codechicken/multipart/MultiPartRegistryCharacterizationTest.java
index 84a97aa..be2c79f 100644
--- a/src/test/java/codechicken/multipart/MultiPartRegistryCharacterizationTest.java
+++ b/src/test/java/codechicken/multipart/MultiPartRegistryCharacterizationTest.java
@@ -149,6 +149,49 @@ class MultiPartRegistryCharacterizationTest {
         assertEquals(2, converter.calls);
     }
 
+    @Test
+    void converterRegistrationCapturesBlocksAndRetainsDuplicateEntries() {
+        Block original = new Block(Material.rock) {};
+        Block later = new Block(Material.rock) {};
+        RecordingConverter converter = new RecordingConverter(Arrays.asList(original, original), null);
+        MultiPartRegistry.registerConverter(converter);
+        converter.blocks.clear();
+        converter.blocks.add(later);
+        MultiPartRegistry.registerConverter(converter);
+
+        assertNull(MultiPartRegistry.convertBlock(null, null, original));
+        assertEquals(2, converter.calls);
+        assertNull(MultiPartRegistry.convertBlock(null, null, later));
+        assertEquals(3, converter.calls);
+    }
+
+    @Test
+    void converterReceivesOriginalPositionAndFailureStopsDispatch() {
+        Block block = new Block(Material.rock) {};
+        BlockCoord pos = new BlockCoord(2, 3, 4);
+        IllegalStateException failure = new IllegalStateException("converter failed");
+        MultiPartRegistry.registerConverter(new IPartConverter() {
+
+            @Override
+            public Iterable<Block> blockTypes() {
+                return Arrays.asList(block);
+            }
+
+            @Override
+            public TMultiPart convert(World world, BlockCoord supplied) {
+                assertNull(world);
+                assertSame(pos, supplied);
+                throw failure;
+            }
+        });
+        RecordingConverter fallback = new RecordingConverter(block, new TestPart());
+        MultiPartRegistry.registerConverter(fallback);
+        assertSame(
+                failure,
+                assertThrows(IllegalStateException.class, () -> MultiPartRegistry.convertBlock(null, pos, block)));
+        assertEquals(0, fallback.calls);
+    }
+
     private static final class RecordingConverter implements IPartConverter {
 
         private final List<Block> blocks = new ArrayList<>();