Inserting with same Ids and performance

So, we are inserting new data over the same Ids in elastic search and it lead it to a red state in the index. With a blockage and data loss.

My questions are: Does reindex over the same Id have any hidden problem over a new Id insert? Does it have a performance issue? (Because I have it with this configuration) Should I use a different configuration?
Any tips on configuration for this matter?

Another question about behavior: As I am updating the same "document" again and again if I ask to retrieve it just after put it to index, Does elastic search returns the document if asked so? For update purposes again.
Search process does not need the immediate response.
Lests say insert 1 -> get 1 -> reinsert 1 with different data -> get 1 (should be version 2) in a very fast manner. Over and over again.

If you are getting via ID then you will get the document even if it hasn't been flushed from the translog.

This shouldn't be causing a problem though, what do your logs show?

Thanks! I'm gonna test it anyway just to peace of mind. Because I've to add bigger queue settings because elastic wasn't performing fast.