That isn’t a solution, that’s wishful thinking. You don’t know how much data wasn’t readable from the file. It’s highly likely at least some parts of the file couldn’t be read, weren’t present in your edit session and are therefore permanently lost.
Sure, you can continue with your setup, but be prepared for issues further down the road.
That being said, you should be able to verify if there are entries missing. I’ve whipped up a script that can verify the presence and correctness of all entries in idmap.ldb by comparing its contents to the users & groups present in the OpenLDAP. Simply download it & run it.