Root Abyss Boss Mechanics

yes, however the fact that due to latency, there's a delay in you moving, and the server recognizing that you moved, would explain why people are getting hit by boss attacks that they already dodged, since it also probably applies to monsters.

so the boss attacks
you get attacked

but you don't get the client notification to play the boss attack until a few seconds later due to lag, and on your screen the boss attacks, but serverside, the attack is already over, and you were just standing there and taking it.

At Pianus (kenta pq) I was seeing damage from his 1/1s way before the animation, assuming I remember correctly what it looks like... it makes it impossible to dodge anything if the animation plays too slow for the damage.