I think it's much easier to cheat programmatically with an emulator.

For example, you could play a game in an emulator and record all input, and save at each new screen. Then if you die or get a bad RNG behavior, restore from the last save (discarding all input since the last save), and continue playing until you beat the screen.

Then, for the record, just replay the 'winning' branch through the CRT and record it.

MAME supports exactly this kind of input recording and playback: https://www.reddit.com/r/MAME/comments/6p0g9o/how_to_record_...