diff --git a/src/main/java/com/github/zly2006/carpetslsaddition/mixin/legacy/FallingBlockEntityMixin.java b/src/main/java/com/github/zly2006/carpetslsaddition/mixin/legacy/FallingBlockEntityMixin.java
index 81b9c6c..e9b2433 100644
--- a/src/main/java/com/github/zly2006/carpetslsaddition/mixin/legacy/FallingBlockEntityMixin.java
+++ b/src/main/java/com/github/zly2006/carpetslsaddition/mixin/legacy/FallingBlockEntityMixin.java
@@ -1,6 +1,7 @@
 package com.github.zly2006.carpetslsaddition.mixin.legacy;
 
 import com.github.zly2006.carpetslsaddition.SLSCarpetSettings;
+import com.github.zly2006.carpetslsaddition.ServerMain;
 import com.github.zly2006.carpetslsaddition.util.LegacyBlockChangeRecorder;
 import net.minecraft.core.BlockPos;
 import net.minecraft.world.level.block.state.BlockState;
@@ -11,13 +12,8 @@ import org.spongepowered.asm.mixin.injection.ModifyVariable;
 /**
  * [旧版] 落沙替换的核心注入点——重建 1.12 的"替换窗口"（记录+回放版）。
  *
- * <p>1.12：{@code BlockFalling} 创建实体时【重读世界】，异步线程在"检查→读取"间改块即可替换。
- * 26.1.2 单线程下该窗口物理不存在（tick 内同步 fall，无让出）。
- *
- * <p>本 mixin 改用 {@link LegacyBlockChangeRecorder}：
- * 当 {@code legacyFallingBlockReplace} 开启时，若该位置在最近 {@code WINDOW_TICKS} 内被改动过，
- * 就用记录的新方块作为下落实体的内容。这样玩家搭建的装置（改变世界方块）会决定下落实体的内容，
- * 与 1.12 的"装置驱动"玩法一致。
+ * <p>当 {@code legacyFallingBlockReplace} 开启时，若该位置在最近 {@code WINDOW_TICKS} 内被改动过，
+ * 就用记录的新方块作为下落实体的内容。这样玩家搭建的装置（改变世界方块）会决定下落实体的内容。
  */
 @Mixin(net.minecraft.world.entity.item.FallingBlockEntity.class)
 public class FallingBlockEntityMixin {
@@ -32,10 +28,13 @@ public class FallingBlockEntityMixin {
         if (!SLSCarpetSettings.legacyExploitMode || !SLSCarpetSettings.legacyFallingBlockReplace) {
             return original;
         }
+        ServerMain.LOGGER.info("[SLSA-DEBUG] fall() pos={} original={}", pos, original.getBlock());
         BlockState recent = LegacyBlockChangeRecorder.getRecentChange(pos);
         if (recent != null && !recent.isAir()) {
+            ServerMain.LOGGER.info("[SLSA-DEBUG] >>> REPLACE at {}: {} -> {}", pos, original.getBlock(), recent.getBlock());
             return recent;
         }
+        ServerMain.LOGGER.info("[SLSA-DEBUG] no recent change at {}, recent={}", pos, recent);
         return original;
     }
 }
\ No newline at end of file
diff --git a/src/main/java/com/github/zly2006/carpetslsaddition/mixin/legacy/FallingBlockMixin.java b/src/main/java/com/github/zly2006/carpetslsaddition/mixin/legacy/FallingBlockMixin.java
index 1bd88be..5a74839 100644
--- a/src/main/java/com/github/zly2006/carpetslsaddition/mixin/legacy/FallingBlockMixin.java
+++ b/src/main/java/com/github/zly2006/carpetslsaddition/mixin/legacy/FallingBlockMixin.java
@@ -34,6 +34,7 @@ public abstract class FallingBlockMixin {
     @Inject(method = "getDelayAfterPlace", at = @At("HEAD"), cancellable = true)
     private void legacyDelayAfterPlace(CallbackInfoReturnable<Integer> cir) {
         if (SLSCarpetSettings.legacyExploitMode && SLSCarpetSettings.legacyInstantFall) {
+            com.github.zly2006.carpetslsaddition.ServerMain.LOGGER.info("[SLSA-DEBUG] getDelayAfterPlace called -> 0");
             cir.setReturnValue(0);
         }
     }
@@ -72,6 +73,7 @@ public abstract class FallingBlockMixin {
     @Inject(method = "tick", at = @At("HEAD"))
     private void legacyTick(BlockState state, ServerLevel level, BlockPos pos, RandomSource rand, CallbackInfo ci) {
         if (SLSCarpetSettings.legacyExploitMode && SLSCarpetSettings.legacyInstantFall) {
+            com.github.zly2006.carpetslsaddition.ServerMain.LOGGER.info("[SLSA-DEBUG] FallingBlock.tick pos={}", pos);
             LegacyExploitState.markInstantFall(pos);
         }
     }