Yeah I don't think this is a good idea. There is only one thoroughly developed mod for Zero-K (Future Wars) that I know of that is (somewhat) balanced that would be suited for this. There's also More Units Mod, and a few but iirc they're not properly balanced for teams. Zero Wars only works with one map and 2-6 players, so that's also not an option. As of Unit Level Ups, over time zero-k version updates have meant things becoming bugged or not working (i.e. lance doesn't fire) and some of the perks don't work. It also has no semblance of balance. You could configure mod options, but you won't get anything up to the level of quality needed for the autohost rooms.
Let me propose a similar idea, events:
- Events are like separate mini-mods. For instance, making mexes gain more metal the time that they're alive. Or metal decay- mexes decay over time. Or volatile units- units release a massive explosion as they die, etc. Things that change the game, but not massively.
- Players can call an '!event' vote for a random event before map start, or '!event <eventname>'
- every 1 in 10 or 1 in 20 matches, the autohost will start an '!event' vote automatically