So, I found a consistent technique for round 31 of the 8-trip run on TurboGrafx, and posted a short video (4 minutes) demonstrating it. The first half, as you can see, is still challenging with the UFO enemies, but this trivializes the second part of the level and turns the game's hardest level into just another part of the run.

Please let me know if you have any questions or feedback. I'd like to do similar work on some of the difficult stages in trips 6 and 7 that are still tricky.