What about initrd? Most of those use busybox and it's now "recommended" to start systemd there. (Granted, I don't see why anyone would run busybox's syslog - the only component affected by this change - in an initrd.)

If you want an extremely small system, you can put everything you need into the initrd. It's not strictly an initrd then, since it's not really used for bootstrapping a larger system image.

This is the only way I use Linux.

I will use the Linux kernel (although it is not my favorite kernel).

But I am interested very little in GNU userlands and all the idiosyncracies, complexity and politics that comes with them.

uhhhh procd?