a map is a key value storage. there is no specific collision handling this is just a "at this key we want this value".
you cannot find the keys in that way, it does not work like that. this is basic memory handling.
a datastructure should be efficient at it's task. so adding a change vector tracking would break the SRP (single responsibility principle). Because mainly it should just store values and have a certain access behaviour.
you need to add a special structure around that tracks the change vectors. Even there you can have different ways of how changes are tracked -> sequencial, distinct.
does this help ?