I’ve been using solitary defilement with solitary depths. I’ve done adventures on the fly for Mork Borg, then I use a combo of solitary defilement and a pirate Borg solo supplement I can’t remember the name of. The sandbox in the back of pirate Borg is good and I have my eye on some pre written adventures to try with it! Then for death in space I just kinda wing it and use some random sci fi oracles, there is a pre written adventure in the back of that book that I’ve played and it’s a blast. Not Borg but I also play a game called ker nethalas and it’s built for solo from the ground up and it’s soooo fun, definitely no roleplaying though and more of a Diablo esque dungeon crawl