Then you can always rollback in case you don’t have a working image.
I had to do that once. On a non-atomic install, this would have meant a completely broken system. In my case, this was one reboot away and it worked again.
And in case you don’t like the direction of your image project going, you can also always rebase to another one in less than 5 minutes, download time and reboot included.
uBlue for example starts with a very basic Fedora Silverblue image, which you can fork easily yourself. I have zero experience in coding or other stuff, and even I managed to get my own custom image working.
There are already a couple of people around who started with Aurora, Secureblue or Bazzite, but then found them too opinionated, and went back to Vanilla Kinoite for example.
It’s extremely simple to switch out the base OS to something almost completely different.
And, you don’t loose any customisability. You can still do everything you want, take a look at Bazzite or Secureblue. Completely different kernel, additional modifications and packages, and much much more. Feels completely different than Vanilla Kinoite for example.