So I was thinking about giving some time to other team if other team manages to get boom res fast.
Saturation of RT's over time (lets say 2-3 min).
So at start RT produces only lets say 0.5 res, after 1 min 0.75, after 2 1res, after 3 min 1.25 res and it says like that on max. That way you would put priority on defending rt's as well as trying to get new ones and would prevent marine whoring map in 1st two minutes of game getting 6 res nodes and living like kidney in honey.
Also would prevent aliens getting too fast lifeforms and would emphasize the first choice of upgrade more directly (so if aliens choose lets say celerity they are stuck with it for a longer time, same if marines decide early shotgun\phasegate would mean same thing).
It's been done in some RTS games like Dawn of War 2 and it was a good system.
Of course those numbers I put would need to be balanced and see how it works, but it gives more time to other team to respond accordingly.