Sadly level 256 is the highest level we can go for, the scoreboard cannot display higher levels. For a new version I was thinking of redoing the XP needed since the jumps right now are quite weird, especially in the lower levels, prestiges were also a thing I had in mind before, but I'd rather keep it simple and just keep it as it is currently with just levels and no prestiges.
Some of the custom weapons have issues when it comes to camos, they display a bit weird depending on what game they originated from, most BO2 weapons work quite okay, Intervention as an example get a quite faded camo, you can barley see it but it's there. Not sure if possible to redo the texture for them, never got the time to do so since I wanted to get as many done as possible, and not just focus on some specifics.
I'm not 100% sure if ZAM 3.0 is at it's max currently, it's very close to it, meaning that it's quite limited in how much things can be added, there's some hardcoded limits in BO1 that cannot be exceeded, however there's a few messy workarounds that I could use to get more barricades into the mod, so it's a possibility, but not sure if I'll do it.