Every time I've think about doing LFS, I come to the same conclusion that Arch is probably good enough to get the same hands-on understanding but without having to do the menial work.
For a great low-commitment experiment with minimalistic Linix, I'd recommend setting up PRoot with Termux on Android and then adding Arch repositories. You can treat it like a replacement for a mobile game and slowly build up your perfect mobile desktop environment.
There is slackpkg for package management, and sbopkg for “ports.” (What is “missing” is dependency management, which often turns out to be a blessing.)
https://wiki.termux.com/wiki/PRoot