OP said they were not looking for Ubuntu or Arch derivatives, and that they were not afraid to get their hands dirty to figure things out. Slackware + Flatpaks can give a stable base while giving you up-to-date applications when SBo doesnt have the build files. This would give OP a system that just works OOTB. Tho it is KDE OOTB, one can put gnome or cinnamon on it.