In The Algorithm the boss fight against Galactic Emperor while the ice drill is breaking down the wall is way, way too long. If memory serves, he hides three times (it may be twice, apologies if I am wrong), so you basically fight him in four stages. Even with a competent team with a Battleborn like Ambra, who has perfect accuracy and thus is great against this boss, it is tedious and simply not fun. However, with a team full of new/unskilled players, it is hellish.
Please consider reducing the number of stages or at least making them more varied so they are more interesting. Right now you do basically the same thing four times, and it ends up being so rote I dread this part.
P.S. I gave Kelvin a try in story and ended up on a team of entirely new players, so I had to basically do the bulk of the damage. As a melee character, especially one as weak him, with minimal support, this battle took well over ten minutes. That may not sound too long, but when you are actually playing that is brutal.