Due to this logic, key image validity will not be checked below the highest checkpoint. So if you want to see if there are any exploits you will need to remove the newly added checkpoints here

Given that there would be little other reason to add those checkpoints now when there were never checkpoints in bitcedi before, I have a suspicion that there were key image exploits, but that is just a guess.

EDIT: I also noticed an explicit block height condition here. That would need to be removed as well if you want to check for earlier exploits.