diff --git a/core/src/main/java/art/arcane/iris/core/pregenerator/IrisPregenerator.java b/core/src/main/java/art/arcane/iris/core/pregenerator/IrisPregenerator.java
index 5a94fa9fd..341328fe2 100644
--- a/core/src/main/java/art/arcane/iris/core/pregenerator/IrisPregenerator.java
+++ b/core/src/main/java/art/arcane/iris/core/pregenerator/IrisPregenerator.java
@@ -284,7 +284,6 @@ public class IrisPregenerator {
                 Mantle mantle = getMantle();
                 if (mantle != null) {
                     mantle.trim(0, 0);
-                    mantle.unloadTectonicPlate(0);
                 }
             }
 
diff --git a/core/src/main/java/art/arcane/iris/core/pregenerator/methods/AsyncPregenMethod.java b/core/src/main/java/art/arcane/iris/core/pregenerator/methods/AsyncPregenMethod.java
index d5665e80f..2b34db5aa 100644
--- a/core/src/main/java/art/arcane/iris/core/pregenerator/methods/AsyncPregenMethod.java
+++ b/core/src/main/java/art/arcane/iris/core/pregenerator/methods/AsyncPregenMethod.java
@@ -91,8 +91,6 @@ public class AsyncPregenMethod implements PregeneratorMethod {
     private final int maxResidentTectonicPlates;
     private final int mantleBackpressureWaitMs;
     private final long mantleBackpressureTimeoutMs;
-    private final long mantleReclaimIntervalMs;
-    private final AtomicLong lastMantleReclaim = new AtomicLong(0L);
 
     public AsyncPregenMethod(World world, int unusedThreads) {
         if (!PaperLib.isPaper()) {
@@ -145,7 +143,6 @@ public class AsyncPregenMethod implements PregeneratorMethod {
         this.maxResidentTectonicPlates = pregen.getMaxResidentTectonicPlates();
         this.mantleBackpressureWaitMs = pregen.getMantleBackpressureWaitMs();
         this.mantleBackpressureTimeoutMs = pregen.getMantleBackpressureTimeoutMs();
-        this.mantleReclaimIntervalMs = 1_000L;
     }
 
     private IrisPaperLikeBackendMode resolvePaperLikeBackendMode(IrisSettings.IrisSettingsPregen pregen) {
@@ -501,31 +498,25 @@ public class AsyncPregenMethod implements PregeneratorMethod {
             return;
         }
 
-        long now = M.ms();
-        long lastReclaimAt = lastMantleReclaim.get();
-        if (now - lastReclaimAt >= mantleReclaimIntervalMs && lastMantleReclaim.compareAndSet(lastReclaimAt, now)) {
-            mantle.trim(0L, 0);
-            mantle.unloadTectonicPlate(0);
-        }
-
-        if (mantle.getLoadedRegionCount() <= cap) {
+        int hardCap = cap * 2;
+        if (mantle.getLoadedRegionCount() <= hardCap) {
             return;
         }
 
         long waitStart = M.ms();
         long lastLog = 0L;
-        while (mantle.getLoadedRegionCount() > cap) {
+        while (mantle.getLoadedRegionCount() > hardCap) {
             mantle.trim(0L, 0);
             int freed = mantle.unloadTectonicPlate(0);
             int resident = mantle.getLoadedRegionCount();
-            if (resident <= cap) {
+            if (resident <= hardCap) {
                 break;
             }
 
             long elapsed = M.ms() - waitStart;
             if (elapsed >= mantleBackpressureTimeoutMs) {
                 Iris.warn("Pregen mantle backpressure exceeded " + mantleBackpressureTimeoutMs + "ms with " + resident
-                        + " tectonic plates resident (cap " + cap + "); proceeding to avoid deadlock. "
+                        + " tectonic plates resident (hard cap " + hardCap + "); proceeding to avoid deadlock. "
                         + "Raise pregen.maxResidentTectonicPlates if this persists. " + metricsSnapshot());
                 return;
             }
@@ -533,7 +524,7 @@ public class AsyncPregenMethod implements PregeneratorMethod {
             long logNow = M.ms();
             if (logNow - lastLog >= 5_000L) {
                 lastLog = logNow;
-                Iris.warn("Pregen mantle backpressure: " + resident + " tectonic plates resident (cap " + cap
+                Iris.warn("Pregen mantle backpressure: " + resident + " tectonic plates resident (hard cap " + hardCap
                         + "), freed " + freed + " last pass, waited " + elapsed + "ms.");
             }
 
diff --git a/core/src/main/java/art/arcane/iris/core/service/IrisEngineSVC.java b/core/src/main/java/art/arcane/iris/core/service/IrisEngineSVC.java
index d566cbc41..c01f923db 100644
--- a/core/src/main/java/art/arcane/iris/core/service/IrisEngineSVC.java
+++ b/core/src/main/java/art/arcane/iris/core/service/IrisEngineSVC.java
@@ -33,7 +33,6 @@ import java.util.concurrent.atomic.AtomicLong;
 
 public class IrisEngineSVC implements IrisService {
     private static final int TRIM_PERIOD = 2_000;
-    private static final long ACTIVE_PREGEN_IDLE_MILLIS = 500L;
     private final AtomicInteger tectonicLimit = new AtomicInteger(30);
     private final AtomicInteger tectonicPlates = new AtomicInteger();
     private final AtomicInteger queuedTectonicPlates = new AtomicInteger();
@@ -188,7 +187,8 @@ public class IrisEngineSVC implements IrisService {
     }
 
     private void add(World world) {
-        var access = IrisToolbelt.access(world);
+        if (world == null || worlds.containsKey(world)) return;
+        PlatformChunkGenerator access = IrisToolbelt.access(world);
         if (access == null) return;
         worlds.put(world, new Registered(world.getName(), access));
     }
@@ -201,6 +201,10 @@ public class IrisEngineSVC implements IrisService {
             @Override
             protected long loop() {
                 try {
+                    for (World world : Bukkit.getWorlds()) {
+                        add(world);
+                    }
+
                     int queuedPlates = 0;
                     int totalPlates = 0;
                     long chunks = 0;
@@ -372,15 +376,11 @@ public class IrisEngineSVC implements IrisService {
                 return limit;
             }
 
-            return Math.max(1, Math.min(limit, Math.max(2, limit / 8)));
+            return Math.max(limit, IrisSettings.get().getPregen().getMaxResidentTectonicPlates());
         }
 
         private long activeIdleDuration(Engine engine) {
-            if (!pregenTargets(engine)) {
-                return TimeUnit.SECONDS.toMillis(IrisSettings.get().getPerformance().getMantleKeepAlive());
-            }
-
-            return ACTIVE_PREGEN_IDLE_MILLIS;
+            return TimeUnit.SECONDS.toMillis(IrisSettings.get().getPerformance().getMantleKeepAlive());
         }
 
         @Synchronized