Foot stabilisation for medium-stage flat feet

I am quote hindered in the weightlifting field due to medical flat feet. I have seen that it has been discussed shoe-wise here before but I am curious if there are other people who have actually *diagnosed* flat feet (disease stage 2a or worse) that could gradually prevent total foot collapse in the bottom of their lifts due to not only orthotics and stuff, but actual foot/leg exercises.

I have seen alot of people on various subreddits saying they have "sort of flat feet" or "weak feet" and all kinds of things worked for them, but I would love to hear if someone who was actually properly *diagnosed* with this (I have adult-acquired flexible flat feet stage 2a/b) found relief from foot strenghtening exercises. Because as of today, the only response I've gotten from my doctor is to surgically reconstruct my entire foot. And I want to try other things first to be able to follow a lifting programme and not become a vegetable.