So... I just wanted to see what would happen if you put more than 100 enemies in one stage. I chose Stage 3, as it is a very long distance between the Normal and Reverse spawn point. It seems that at 80+ enemies, there are no more normal CPU files (79 regular CPU's and 1 Boss CPU) to use for other enemies and it defaults to Guest A (but with red?) and Saburo in Gold Armor (with green armor behavior?). The emulator will spam invalid reads, but just holding enter let's you keeping going. At 100+ enemies, the game thinks that it's another stage and resets the armor choices, but still has Guest A and Saburo, but also has some random normal CPU's mixed in. At 180+ enemies, it repeats. What's interesting is that there's unused data for 35 more enemies past the regular 35 in the base game, including Purple Armor, which could mean that you could have seen Purple Armor as early as Stage 3!

Chapters:
0:00 180 (Normal)
2:17 80100
2:45 100180
4:57 180200