Undimple tne flanges. Then countersink them.
The flanges are 5052H32 or something similarly soft.
If you really bugger up a flange hole, just use an “oops” rivet or a shop-made “swelled shank” rivet. Of course you will have to drill up the receptacle too, but I doubt you will have any issues with the undimple and countersink. I think I did a lot of mine freehand with the piloted CS bit and swivel deburring handle.
In the future, if you think you have discovered a design flaw on something that has been successfully installed thousands of times, you might want to take a break or ask the gang first.