Honestly, although I wouldn't mind staying in the Siberia setting, I think it can work on the main server. Maybe make plasmagats less common, buff Terminators up abit, and focus more on s2rp and undecided battles. Rather than make it so one side is guaranteed to win or lose, it can be decided based off how the actual fight goes. Give skirmishes more weight, make scavengers less dependent on TC and their big boy guns. Stuff like that is appealing, atleast to me. That, and more ingame effects from the happenings of the world. Maybe if a reconbot gets taken out, they'll stop scouting areas for abit, but as a counter, some regular infantry automatons might roll out and check around for what killed the reconbot. Just small, ambient stuff to help make things feel more lively.
Also, one more thing, having ballistics be more viable as a sort of in general thing would be nice. They're usually overlooked, but something like a Mosin would probably have a good effect, even on things like 800s.
As for the event itself, (rather than things I'd like to see implemented from it) the only mildly bad thing I have to say about it is day 1 was rather slow. Ammo was also just a smidge too rare for my liking, and some of the banditos were abit too much. Past that, it was amazing. Every character could have an impact because of how scaled down everything was. It wasn't just a squad of some TC or people with donator guns wiping the floor while scavengers did fuckall damage, it was a constant cooperative effort to take down some bots. Terminators, even something like 600s, were what the name implied, they were something to fear. If you got caught out in the open by one, you had to run. At the same time, ballistics could actually do some serious damage. You weren't helpless if you didn't have some 60watt with 500 plasmacellthingys, you could have a very real effect on how battles went. It was great.
As a plus, there wasn't any trash tier stalger characters, so that was nice.