[Pax]

I had an idea recently: each person designs their own racial tech area, with all dependant techs, components, mounts, facilities, etc.

Yes, sort of a god-modding affair. But with one catch: research costs, possibly even racial trait costs, would be tweaked for overall balance by an impartial, nonplaying "arbiter" ...

But that way, you wouldn't know what a given alien race was TRULY capable of, until you witnessed that capability for yourself ... typically by getting them to shoot at you. Heh.

Unlike currently, where you can almost 100% expect certain things from, say, an Organic Manipulation race.

Not EXACTLY what you're thinking of, but related, IMO ...