Replace nextPosToSearchFrom with lowestPossiblyFreeChunk semantically, that allows to avoid searching free chunks though a full tier, when segment is tiered, again and again. Also, make chunk block reallocation in innerDefaultReplaceValue() and putValueDeletedEntry() check it doesn't overflow actualChunksPerSegmentTier

src/main/java/net/openhft/chronicle/map/ChronicleMapBuilderPrivateAPI.java

@@ -53,8 +53,8 @@ class ChronicleMapBuilderPrivateAPI<K> implements ChronicleHashBuilderPrivateAPI
     }
 
     @Override
-    public long actualChunksPerSegment() {
-        return b.actualChunksPerSegment();
+    public long actualChunksPerSegmentTier() {
+        return b.actualChunksPerSegmentTier();
     }
 
     @Override