I'm remodeling a small bathroom on a slab and the flange appears slightly damaged - the slot in the flange looks slightly enlarged and I'm concerned that the normal bolts might pull through. I definitely don't want to replace the flange. I could use a piece of stainless threaded rod and a stainless washer and self-locking nut in place of the bolt. The washer would be larger than the normal bolt head.

Does this sound as though it might work?