So, when you say crippled kernel, do you actually mean you tweaked the kernel params/build to the point that it failed to boot? Or do you just mean you messed up some package config to the point that the normal boot sequence didn’t get you to a place you knew how to recover from and need to reinstall from scratch?

I think I’m past the point where I need to do a full reinstall to recover from my mistakes. As long as I get a shell, I can usually undo whatever I did. I have btrfs+timeshift also set up, but I’ve never had to use it.