Instead of increasing it by X amount of pounds considering anything above a certain pound difference is an automatic match cancellation anyway, what if we did this?
If you miss weight, you can still compete, but if YOU win, it counts as a No Contest on your record and you're fighting for your show money and your opponent gets half your win bonus and half goes to the athletic commission so it would enforce them to keep a strict eye on weight, and it would incentivize fighters to make sure they make weight every time, otherwise they're fighting for a No Contest at best. This would increase fighter safety as well because they wouldn't take as many risks with their weight and they'd fight closer to their natural weight by 5 or so pounds, putting less strain on their bodies and increasing their energy tank anyway, thus leading to more exciting fights for the fans.
Everyone wins.