I can attack phase 1 with the chain shot. But as far as I can tell, every boss has a brief moment of invulnerability. It just so happens that phase 1 moves so quickly that it's just barely possible to even reach to hit a second time. Most of the time, that's too short for the invulnerability to be gone. But it's tight either way.
Honestly, I'm not sure if that needs fixing. Of course it would be nice for everything to be perfectly executable with 0 RNG, but currently only I seem to run it in any serious capacity. So it doesn't really matter in the end if I can two cycle phase 1 if the RNG can swing for 4 attacks each cycle (as compared to the WR phase 1 which I think only had 2 attacks total over 4 cycles?). I'd rather see how the speedrun develops in the near future instead of rushing to fix things that may just need to be understood correctly.
Thank you so much for engaging with the speedrun side and offering your help! It already means a lot that you even watch the speedruns at all :3
And I'll take you up on that offer once I actually get consistent (and maybe more people submit runs) ^^