Whenever i play UBP i find that aliens, unless outclassed by a human team containing a couple of players who aren't totally inept(bearing in mind the kind of people who find UBP entertaining, severe levels of ineptitude are to be expected), and assuming standard trem maps rather than some of the hilariously poor ones that are often in rotation on these lolservers, will turn around and completely decimate the human turret spam at SD, if not before, marazap, and a bit of sniping where necessary, really makes it quite straightforward.
Attempting to balance ubp is a total waste of time, as is playing the thing, both teams build and feed until SD, then camp hard until their bases are whittled away to nothing, simply horrible.
On seconds thoughts, yes, do make such a mod, anything that slows down the building process has the potential to make UBP fans lose interest and play the sims instead.