From my hazy memory, so please, mind the gap between my wording and what Scawen really wrote:
Scawen explained back then, that to change tyre compound, or do some of setup changes (camber, etc..), he has to recreate the physical model of suspension and he can't apply the same damage it had before to it because it's different after changes to setup (IIRC the tyre compound may change some center positions/diameters and weight mass, so it needs suspension in "clean" state to initialize properly), so basically he can't easily fix this, actually it did sound more like it can't be fixed at all in "proper" way.
Maybe he will figure out some appropriate trade off how to recreate adequate damage to the newly initialized physics after changes, but I wouldn't bet on it.
About F1 races: from my limited demo experience (mostly FBM) I would say it's impossible to gather damage as long as you don't hit anything and don't jump over curbs or drive over holes... which I always do. In longer races where everyone must change tyre type probably everyone gets unwanted repair, so it's sort of fair? Anyway, this is real problem, but not easy to fix with the current LFS physics system.