@sicp You know what would be a good idea? Dual booting one systemd-less distro with another! GRUB exists for a reason, y'know? If I want to use Void, I could do that. If I want to use Slackware, the ol' reliable since '93, I could go right ahead and shove it onto a seperate SSD. Thanks for the suggestion, guujyon!
@tsubocchi I always just used LILO since it's what the Slackware installer recommends and it works (it gives you both options), whereas GRUB is a PITA to set up correctly.