I did my second raid run two days ago and have some more things to add.
I wanted to say this myself. Stone Grip damage requirements do not scale right, or at all. My test run group was at 28 people for this boss and Thursday raid 15. The damage requirement was the same for both raids and smaller raid could not break grip until we added more dps.
There is aslo another issue on Mimiron. With the pull he will just attack you will doing his dialogue. Why is this bad? Well you can’t attack him until Mim stops talking and 1-2 people will die.
Lastly General Vezax’s mark of the faceless has not scaled at all to fit BFA. It will 3 shot players and heal the boss for 4% heath per tick from one player that was stolen life. It makes the encounter like auto hard mode. But the only nice thing is mark is attacking ranged only for some reason.