I wish people would stop coming to crazy solutions. If something is not working on the car, you don't stop everything and put everyone on that one thing to develop it. If for example, the tyres aren't understood, you don't stop everyone in aero/transmission/vehicle dynamics and put them on a tyre development project. Most are not suitably skilled to do this, especially with tyres. This is what tyre engineers are supposed and skilled to do. If there was one really good tyre engineer that got the tyres working very well and Mercedes started winning, you guys would jump to the other conclusion that the engineers were great.
There is also a post about elastokinematics by someone, you are very ill-informed if you think this would be a really easy thing to do. And everything you do in parc-ferme is recorded by the FIA, photos taken sometimes and all documented at the end of the weekend. So if you adjust this bolt every race in parc-ferme, there would be documents every race saying and showing you adjusted the same bolt every time. If you were going to try something like this, there are far more elegant solutions, such as putting a secondary spring inside the damper housing which is adjusted by a bolt on the outside.
Things these days are not easy to do, they may seem simple but believe me, there's always a 100 things about the item you'd have never though about. No in-season testing increases the risk and slows down development.