On one playthrough long ago (on a PC/XT!), I made it to Finster's Mind Maze. For some reason lost to time, either because he was the only one with Cyborg Tech or too many of my other characters were badly injured, I ended up sending COVENANT (the NPC) as the one Ranger into the Maze.
This worked great until he got stuck somehow. I can't remember the exact details, but it was beyond the point of no return and I think it had to do with him being an NPC - couldn't control what he was doing, so he got killed. As a result I had to bail on the entire save. Couldn't finish the maze, couldn't get him out. Sucked.