OpenRA

Basically this, making multiple heavy factory actually speed up things rather than stay the same (like current Dune2000 mod in OpenRA)

You know, Dune 2000 rarely have players in MP, so if I want to play dune2k, I must play in SP most of the time (or the other, original Dune2k, but that's another question). And with current settings, fighting against 3 AI (they're in a group against me alone) is nigh impossible (due to they basically have triple production rate, unless I rushed one early on and left the two for later)

I thought about making light and large vehicle factory one queue, but with speedups when you have multiple to keep a balance between spam and honoring investment into additional base buildings.

That would be good, like soviet Barracks and Kennel.

But then, the Light factory actually is the one of the most interesting point in Dune, when you can build light scout/raiding unit without compromising the production of your main "backbone" unit aka combat tank and harvesters. But yeah, there's starport too...

what about keeping light factory separate, but speeding up when you have multiple heavy or light factory? I didn't have anything against grouping light and heavy factory into one group though, since there's starport for that...

and anyway, in Dune2K MP, I rarely build light factory, unless I'm ordos. Quads and Trikes could be bought in Starport, and they're faster that way.