Testing goes stabler and stabler with time. Then testing move to release and the previous untesting (sid) move to testing. It’s a that moment that you can have surprise. This is the moment where I often wait one month or two, apply the updates and check my os is working as before, meaning running my day to day applications and game and see if things work. The only problem I had once was shader cache. I removed few things in .cache and I was good.