This boss fight is full of things that can cause a wipe due to the enemies' behaviour, making it feel like it's more RNG than actual skill.
Anyways, the stars aligned for me in this run and I managed to finally clear it.
Took me around 17.5 hours of practice and 1 final stand wipe to get it.

Shoutout to Sojuski for giving me some tips:
   / @sojuski