Maybe I am just tired about the fact I use units well and some dumb one outecoes me and rush T2 because he took somebody or some newbe donated metal to him.
Buildable Space is sure a limit how save your eco is from bombers through redundancy, no chaining, etc, but often not the real limit with T2 adv. fusions on maps with low wind.
UnitLimit always works, but it is better to limit units by:
* how many can shoot at the same time or
* how many constructors don't reclaim the rock in front of each other and make themselves more ineffective in numbers (previously I said I want something like 1/2 time walk, 1/2 reclaim for asteroids distances/value).
* how many radar/jammer, long-range visual sensors do you need? Just 1 per army if you can keep it easily :)
One limit is build power - get more outposts for more cheap, but space-inefficient energy sources, but if you have too many, you need to distribute your limited income too much and can't hold them -> enemy gets free reclaim.
You can bypass this limit by spaming T0 units (only cost metal) but you have to play well to get the reclaim back and reproduce them before the enemy gets your 100% of reclaim