diff --git a/core/src/mindustry/ai/WaveSpawner.java b/core/src/mindustry/ai/WaveSpawner.java
index a895af863f..40be2defad 100644
--- a/core/src/mindustry/ai/WaveSpawner.java
+++ b/core/src/mindustry/ai/WaveSpawner.java
@@ -21,6 +21,7 @@ import static mindustry.Vars.*;
 public class WaveSpawner{
     private static final float margin = 40f, coreMargin = tilesize * 2f, maxSteps = 30;
 
+    private int tmpCount;
     private Seq<Tile> spawns = new Seq<>();
     private boolean spawning = false;
     private boolean any = false;
@@ -162,6 +163,18 @@ public class WaveSpawner{
         }
     }
 
+    public int countGroundSpawns(){
+        tmpCount = 0;
+        eachGroundSpawn((x, y) -> tmpCount ++);
+        return tmpCount;
+    }
+
+    public int countFlyerSpawns(){
+        tmpCount = 0;
+        eachFlyerSpawn((x, y) -> tmpCount ++);
+        return tmpCount;
+    }
+
     public boolean isSpawning(){
         return spawning && !net.client();
     }
diff --git a/core/src/mindustry/game/Schematics.java b/core/src/mindustry/game/Schematics.java
index 0a91c9d1b3..011d289f05 100644
--- a/core/src/mindustry/game/Schematics.java
+++ b/core/src/mindustry/game/Schematics.java
@@ -33,6 +33,7 @@ import mindustry.world.blocks.power.*;
 import mindustry.world.blocks.production.*;
 import mindustry.world.blocks.sandbox.*;
 import mindustry.world.blocks.storage.*;
+import mindustry.world.blocks.storage.CoreBlock.*;
 import mindustry.world.meta.*;
 
 import java.io.*;
@@ -450,6 +451,10 @@ public class Schematics implements Loadable{
             if(st.block instanceof Drill){
                 tile.getLinkedTiles(t -> t.setOverlay(resource));
             }
+
+            if(tile.build instanceof CoreBuild cb){
+                state.teams.registerCore(cb);
+            }
         });
     }
 
diff --git a/core/src/mindustry/game/Waves.java b/core/src/mindustry/game/Waves.java
index bdd95abedf..415ccea8fc 100644
--- a/core/src/mindustry/game/Waves.java
+++ b/core/src/mindustry/game/Waves.java
@@ -261,6 +261,10 @@ public class Waves{
     }
 
     public static Seq<SpawnGroup> generate(float difficulty, Rand rand, boolean attack){
+        return generate(difficulty, rand, attack, false);
+    }
+
+    public static Seq<SpawnGroup> generate(float difficulty, Rand rand, boolean attack, boolean airOnly){
         UnitType[][] species = {
         {dagger, mace, fortress, scepter, reign},
         {nova, pulsar, quasar, vela, corvus},
@@ -268,6 +272,12 @@ public class Waves{
         {flare, horizon, zenith, rand.chance(0.5) ? quad : antumbra, rand.chance(0.1) ? quad : eclipse}
         };
 
+        if(airOnly){
+            species = Structs.filter(UnitType[].class, species, v -> v[0].flying);
+        }
+
+        UnitType[][] fspec = species;
+
         //required progression:
         //- extra periodic patterns
 
@@ -281,7 +291,7 @@ public class Waves{
 
         Intc createProgression = start -> {
             //main sequence
-            UnitType[] curSpecies = Structs.random(species);
+            UnitType[] curSpecies = Structs.random(fspec);
             int curTier = 0;
 
             for(int i = start; i < cap;){
@@ -326,7 +336,7 @@ public class Waves{
 
                 //small chance to switch species
                 if(rand.chance(0.3)){
-                    curSpecies = Structs.random(species);
+                    curSpecies = Structs.random(fspec);
                 }
             }
         };
diff --git a/core/src/mindustry/maps/planet/SerpuloPlanetGenerator.java b/core/src/mindustry/maps/planet/SerpuloPlanetGenerator.java
index 0effbc80f2..112838d405 100644
--- a/core/src/mindustry/maps/planet/SerpuloPlanetGenerator.java
+++ b/core/src/mindustry/maps/planet/SerpuloPlanetGenerator.java
@@ -490,7 +490,8 @@ public class SerpuloPlanetGenerator extends PlanetGenerator{
         state.rules.waves = sector.info.waves = true;
         state.rules.enemyCoreBuildRadius = 600f;
 
-        state.rules.spawns = Waves.generate(difficulty, new Rand(), state.rules.attackMode);
+        //spawn air only when spawn is blocked
+        state.rules.spawns = Waves.generate(difficulty, new Rand(sector.id), state.rules.attackMode, state.rules.attackMode && spawner.countGroundSpawns() == 0);
     }
 
     @Override
diff --git a/core/src/mindustry/net/ArcNetProvider.java b/core/src/mindustry/net/ArcNetProvider.java
index ba8ff4cfa0..4cc05ecccb 100644
--- a/core/src/mindustry/net/ArcNetProvider.java
+++ b/core/src/mindustry/net/ArcNetProvider.java
@@ -342,24 +342,9 @@ public class ArcNetProvider implements NetProvider{
         //for debugging total read/write speeds
         private static final boolean debug = false;
 
-        ThreadLocal<ByteBuffer> decompressBuffer = new ThreadLocal<>(){
-            @Override
-            protected ByteBuffer initialValue(){
-                return ByteBuffer.allocate(32768);
-            }
-        };
-        ThreadLocal<Reads> reads = new ThreadLocal<>(){
-            @Override
-            protected Reads initialValue(){
-                return new Reads(new ByteBufferInput(decompressBuffer.get()));
-            }
-        };
-        ThreadLocal<Writes> writes = new ThreadLocal<>(){
-            @Override
-            protected Writes initialValue(){
-                return new Writes(new ByteBufferOutput(decompressBuffer.get()));
-            }
-        };
+        ThreadLocal<ByteBuffer> decompressBuffer = Threads.local(() -> ByteBuffer.allocate(32768));
+        ThreadLocal<Reads> reads = Threads.local(() -> new Reads(new ByteBufferInput(decompressBuffer.get())));
+        ThreadLocal<Writes> writes = Threads.local(() -> new Writes(new ByteBufferOutput(decompressBuffer.get())));
 
         //for debugging network write counts
         static WindowedMean upload = new WindowedMean(5), download = new WindowedMean(5);
diff --git a/core/src/mindustry/net/Net.java b/core/src/mindustry/net/Net.java
index 9081b194f4..2463c8fed9 100644
--- a/core/src/mindustry/net/Net.java
+++ b/core/src/mindustry/net/Net.java
@@ -274,6 +274,7 @@ public class Net{
             builder.add(c.data);
 
             ui.loadfrag.setProgress(builder.progress());
+            ui.loadfrag.snapProgress();
             netClient.resetTimeout();
 
             if(builder.isDone()){
diff --git a/core/src/mindustry/ui/Bar.java b/core/src/mindustry/ui/Bar.java
index d8e2b4b6da..eb4fcf9a54 100644
--- a/core/src/mindustry/ui/Bar.java
+++ b/core/src/mindustry/ui/Bar.java
@@ -62,6 +62,10 @@ public class Bar extends Element{
         update(() -> this.name = name.get());
     }
 
+    public void snap(){
+        lastValue = value = fraction.get();
+    }
+
     public Bar outline(Color color, float stroke){
         outlineColor.set(color);
         outlineRadius = Scl.scl(stroke);
diff --git a/core/src/mindustry/ui/fragments/LoadingFragment.java b/core/src/mindustry/ui/fragments/LoadingFragment.java
index fcd18dfcbe..4f977fa644 100644
--- a/core/src/mindustry/ui/fragments/LoadingFragment.java
+++ b/core/src/mindustry/ui/fragments/LoadingFragment.java
@@ -56,11 +56,16 @@ public class LoadingFragment extends Fragment{
         bar.set(() -> ((int)(progress.get() * 100) + "%"), progress, Pal.accent);
     }
 
+    public void snapProgress(){
+        bar.snap();
+    }
+
     public void setProgress(float progress){
         progValue = progress;
         if(!bar.visible){
             setProgress(() -> progValue);
         }
+
     }
 
     public void setButton(Runnable listener){
diff --git a/gradle.properties b/gradle.properties
index 52e61753e2..5eb904834f 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -11,4 +11,4 @@ android.useAndroidX=true
 #used for slow jitpack builds; TODO see if this actually works
 http.socketTimeout=80000
 http.connectionTimeout=80000
-archash=4582339cd9052be86141fbacf2f2180b09eb585c
+archash=0d9a003fc8f70b58f739bfacc3817b4c2522a8af