diff --git a/convex-core/src/main/java/convex/core/data/ACell.java b/convex-core/src/main/java/convex/core/data/ACell.java
index 17723f066..4d115bff8 100644
--- a/convex-core/src/main/java/convex/core/data/ACell.java
+++ b/convex-core/src/main/java/convex/core/data/ACell.java
@@ -107,8 +107,8 @@ public int hashCode() {
 	
 	@Override
 	public final boolean equals(Object a) {
-		if (a==this) return true;
-		if (!(a instanceof ACell)) return false;
+		if (a==this) return true; // Fast path, avoids cast
+		if (!(a instanceof ACell)) return false; // Handles null
 		return equals((ACell)a);
 	}
 	
@@ -270,7 +270,8 @@ protected long calcMemorySize() {
 		if (!isEmbedded()) {
 			// We need to count this cell's own encoding length
 			// Plus overhead for storage of non-embedded cell
-			result=Utils.memoryAdd(result,getEncodingLength()+Constants.MEMORY_OVERHEAD);
+			long encodingLength=getEncodingLength();
+			result=Utils.memoryAdd(result,encodingLength+Constants.MEMORY_OVERHEAD);
 		} 
 		return result;
 	}
@@ -311,6 +312,7 @@ public final long getMemorySize() {
 	 * @return true if Cell is embedded, false otherwise
 	 */
 	public boolean isEmbedded() {
+		if (memorySize==Format.FULL_EMBEDDED_MEMORY_SIZE) return true;
 		if (cachedRef!=null) {
 			int flags=cachedRef.flags;
 			if ((flags&Ref.KNOWN_EMBEDDED_MASK)!=0) return true;
@@ -555,6 +557,7 @@ public static <T extends ACell> Ref<T> createPersisted(T value) {
 	 * @return true if completely encoded, false otherwise
 	 */
 	public boolean isCompletelyEncoded() {
+		if (memorySize==Format.FULL_EMBEDDED_MEMORY_SIZE) return true; // fast path
 		if (!isCanonical()) {
 			throw new Error("Checking whether a non-canonical cell is encoded. Not a good idea, any ref assumptions may be invalid: "+this.getType());
 		}
diff --git a/convex-core/src/main/java/convex/core/data/ASymbolic.java b/convex-core/src/main/java/convex/core/data/ASymbolic.java
index 1cf4e9614..758b5b2ef 100644
--- a/convex-core/src/main/java/convex/core/data/ASymbolic.java
+++ b/convex-core/src/main/java/convex/core/data/ASymbolic.java
@@ -12,6 +12,7 @@ public abstract class ASymbolic extends ACell {
 
 	protected ASymbolic(StringShort name) {
 		this.name =  name;
+		this.memorySize=Format.FULL_EMBEDDED_MEMORY_SIZE;
 	}
 	
 	@Override
diff --git a/convex-core/src/main/java/convex/core/data/AccountKey.java b/convex-core/src/main/java/convex/core/data/AccountKey.java
index 001b66459..aa3709e8b 100644
--- a/convex-core/src/main/java/convex/core/data/AccountKey.java
+++ b/convex-core/src/main/java/convex/core/data/AccountKey.java
@@ -26,6 +26,7 @@ public class AccountKey extends AArrayBlob {
 
 	private AccountKey(byte[] data, int offset, int length) {
 		super(data, offset, length);
+		this.memorySize=0;
 		if (length != LENGTH) throw new IllegalArgumentException("AccountKey length must be " + LENGTH + " bytes");
 	}
 	
diff --git a/convex-core/src/main/java/convex/core/data/Format.java b/convex-core/src/main/java/convex/core/data/Format.java
index 7cb5ab0a8..a0ad9791b 100644
--- a/convex-core/src/main/java/convex/core/data/Format.java
+++ b/convex-core/src/main/java/convex/core/data/Format.java
@@ -80,6 +80,11 @@ public class Format {
 	 */
 	public static final long MAX_MESSAGE_LENGTH = 20000000;
 
+	/**
+	 * Memory size of a fully embedded value (zero)
+	 */
+	public static final long FULL_EMBEDDED_MEMORY_SIZE = 0L;
+
 	/**
 	 * Gets the length in bytes of VLC encoding for the given long value
 	 * @param x Long value to encode
diff --git a/convex-core/src/main/java/convex/core/data/prim/CVMBigInteger.java b/convex-core/src/main/java/convex/core/data/prim/CVMBigInteger.java
index c4fd0ffe1..5495ea6cb 100644
--- a/convex-core/src/main/java/convex/core/data/prim/CVMBigInteger.java
+++ b/convex-core/src/main/java/convex/core/data/prim/CVMBigInteger.java
@@ -8,6 +8,7 @@
 import convex.core.data.Blob;
 import convex.core.data.BlobBuilder;
 import convex.core.data.Blobs;
+import convex.core.data.Format;
 import convex.core.data.Strings;
 import convex.core.data.Tag;
 import convex.core.exceptions.BadFormatException;
@@ -229,7 +230,7 @@ protected long calcMemorySize() {
 	
 	@Override
 	public boolean isEmbedded() {
-		if (memorySize==0) return true;
+		if (memorySize==Format.FULL_EMBEDDED_MEMORY_SIZE) return true;
 		return blob().isEmbedded();
 	}
 	
diff --git a/convex-core/src/main/java/convex/core/data/prim/CVMChar.java b/convex-core/src/main/java/convex/core/data/prim/CVMChar.java
index bac497622..d01f9ef49 100644
--- a/convex-core/src/main/java/convex/core/data/prim/CVMChar.java
+++ b/convex-core/src/main/java/convex/core/data/prim/CVMChar.java
@@ -7,6 +7,7 @@
 import convex.core.data.AString;
 import convex.core.data.Blob;
 import convex.core.data.BlobBuilder;
+import convex.core.data.Format;
 import convex.core.data.Strings;
 import convex.core.data.Tag;
 import convex.core.data.type.AType;
@@ -47,6 +48,7 @@ public final class CVMChar extends APrimitive implements Comparable<CVMChar> {
 	
 	private CVMChar(int value) {
 		this.value=value;
+		this.memorySize=Format.FULL_EMBEDDED_MEMORY_SIZE;
 	}
 	
 	@Override
diff --git a/convex-core/src/main/java/convex/core/data/prim/CVMLong.java b/convex-core/src/main/java/convex/core/data/prim/CVMLong.java
index bbd0dba0f..f22ec31c8 100644
--- a/convex-core/src/main/java/convex/core/data/prim/CVMLong.java
+++ b/convex-core/src/main/java/convex/core/data/prim/CVMLong.java
@@ -49,6 +49,7 @@ public final class CVMLong extends AInteger {
 	
 	public CVMLong(long value) {
 		this.value=value;
+		this.memorySize=Format.FULL_EMBEDDED_MEMORY_SIZE;
 	}
 
 	/**