it has down side, u can't rush anything as the cost of tech is not skippable like weapons upgrades
Yeah, in theory, if you don't really care about actually winning the game or even be competitive by 8th minute, I guess you could do that.
But just because you can, doesn't mean its a good idea.
If you're getting weapon upgrades as USF before tiering and ambulance, you're clueless.
In UKF case its even more stupid as sections need to rely on that AEC pretty damn fast now as they aren't dominating anything anymore by themselves and need support, early weapon unlock is only going to delay your tech and bite you in the ass.
Free unlock with tech really does not have any downside, no matter how you want to put it out.
ex ukf can bring centaur out by 145 fuel, usf can rush to lv m20 and stuart (like it always does in all top lvl games) u can't do that to with okw, and similarly with osther , while u can rush a ostwind at the same time as a centaur u will have to skip tier 1 and 2 losing both lmg ,snares and nades + all the units from tech