> As I said, I only get the 1 block leak with a micro test of a class or method.

Yeah, again, the memory block check is fragile. It might be an legit internal cache filled for good reasons. It can be a free list. It can be a lot of things. It's really hard to track such very tiny memory allocation. "leaked [1, 1, 1, 1] memory blocks" can be a false alarm, it's not big.