As for Linux from Scratch - This is something that's been on my radar, but without the part I'm truly interested in (learning more about SysV) then I'm less inclined to bother. I don't buy the reason of Gnome/KDE - isn't LfS all about the basics of the distro than building a fully fledged system? If it's the foundation for the other courses, but it still feels weak that it's so guided by a future GUI requirement for systemd when it's talking about building web servers and the like in a 500Mb or less as the motivation.
If different choices were available for init, DNS resolver, service control manager, volume manager, etc... we would adversely contribute to the schizo distro landscape the people holding the money bags are actively trying to get away from.
With systemd it's an all-or-nothing deal. You get the good with the bad, but all distros shit the bed in the same, deterministic way.
Not even Windows does this. There is no "systemd" equivalent. Yes, Windows ships as a single OS—as do the BSDs—but all the components were developed separately.
If all they wanted was a service control manager, there were many (better) options already in existence they could have used.
For example, not all distros ship and use systemd-resolved by default, to choose from your list.