I had max modifiers on except for the +5 for bow - I picked a +4 instead because I dont have a good bow build. I even had brawn on, which I've seen YT'ers not have when they got into the 1 %. Conclusion, everything is down to whether or not the bonus boss spawns....and I've had a lot of runs now without it spawning. So, another RNG event. And holy crap there's been some "drone runs" - felt like every two enemies had drones. Everything is just down to luck if you can run it. Not using any of the YT melee builds btw. I also have this working theory that there's a score threshold outside of the population percentages. Edit; After another 20 or so runs without a HVT...and I'm done with this event.