When we reach the end of the lab, can we consider this mod is ended ? or is there another challenge ? we reached the end game way before technologie and we played at nomad difficulty. It wasn't really hard to win. Maybe some true boss zombie with 40k life , hugh speed etc... are needed. We held every day 7 without serious trouble. We won without end game stuff like laser gun rifle and so on.
I think it's too bad to win without the need of the best tools / weapon.