Seems that eye boss uses the RNG to determine when to open those eyes after the first time. I have not figured out how to prevent an eye from spawning, though I did figure out how to get those eyes to open exactly when I wanted them to. The time they take to close again is fixed, that can't be manipulated. 10 HP, only enough time for nine shots before they close, but they can re-open very quickly.
The last stage is tiring. Was not a fun thing to TAS when I've got a lot of time for interesting nothings in particular.
Note my weapon bar is draining the whole time. The game forgot to shut off the Anti-Gravity I had. Has absolutely no effect here either way, so it empties without any interference.