Memory manager should not use `.equals` to compare objects

The `MemoryManager` is using a `List` which ultimately means that `.equals` is being used to compare values in methods such as `persist`. Instead, we should use an Array or some structure that uses `==` to compare values. This is because two Objects that are created, much be released independently, regardless if they are `.equals()` or not.

Locate the MemoryManager implementation and inspect persist and the other methods that compare or release objects. Trace how the List is used and identify the existing lifecycle behavior for distinct but equal objects. Done means object tracking and release use identity rather than equality, with coverage for independently releasing equal objects.

Written by the indexing model from the issue text.