I do think there is some weird RNG going on with that last mission because I barely ever died playing the game. I had a set of abilities I used throughout that worked both against crowds and single bosses and was able to breeze through most encounters. In that final segment with the 4 terminals the amount of enemies being spawned seemed broken. At one point I had about 10-20 of the feral elites that lunge at you and launch missiles show up out of nowhere on top of everything else. I ended up beating it because on that attempt it spawned about half as many ferals and there were bigger pauses between waves as I hacked the terminals.
I mean with everything else I experienced in the Ascent it’s not shocking that something was out of whack. If I quit back to the menu and reloaded it would have probably been a different story. I remember finishing 3/4 of a main story mission without encountering a single baddie cause the game just stopped spawning them but all the checkpoints and story triggers worked just fine.