The fact that mission length helps determine spawn rate is just such a stupid fucking design decision. WTF is the point of killing anything if it's just wasting time and thus ramping up your spawn time? I get that POIs and such should increase enemy presence a bit(as well as the "horde" effect when you drop support weapons, etc.), but spawn rate should be a mostly consistent modifier based on difficulty chosen. So if let's say you had a 250% increased spawn modifier on Helldive difficulty, each time your team pops a small nest it should drop it by 5% or whatever. 10% for a medium nest, 15% for a large. I've literally watched a group of mobs spawn right on top of me out of thin air. Not "near" me, right on top.
Obviously those numbers could be adjusted, but those design decisions really make me think these guys have very little idea wtf they're doing and kinda just winging it.
And yet despite all that, the game is still a blast when I'm not crashing 30 times a night. We've pretty consistently been able to do 9s now, but you really can't engage in many fights on Helldive. The spawning gets so fucking out of control it's basically just hitting the objective ASAP, dropping a stratagem behind you while sprinting the fuck away, trying to lose agro. It also seems the game gets "confused" when you split up into 2, 2-man teams and work through the map that way. It's like it doesn't know where to throw the spawns at and just doesn't spawn at all instead. We've noticed a massive reduction in enemies when we do that.