5 seconds I believe.
10 seconds and returns nothing.
See, this is called being retarded.
ML-20, and for that matter, any other static battery counterplay is done through doctrinal picks. You see stuka or il 2 precision in the enemy loadout? Wait before going artillery.
Picking AS has no counterplay for OKW trucks. You are literally forced to not build CORE tech structures in advantageous positions (and if you give me that dumb bullshit about building it in the base, then why does the mech hq have a forward retreat point?).
idk. it doesn't really bother me a whole lot. on one hand, it doesn't have any counter play, which is bad, but on the other hand there are plenty of other things that cause a lot of damage to everyone else's base with little or no counter play. the only thing that's different here is that OKW is designed to be able to build outside their base sector.
while i don't feel that air supremacy should be destroying OKW's buildings in one pass (its 250 mun iirc) i also don't feel like there's a whole lot that can be done about it since it's scatter based. if you reduce the damage you could get shitty RNG runs were it does pretty much nothing or you could still end up with good rolls that wipe the bases anyway.
the other thing is that while you can't counter the ability (short of never letting them get LoS, lol...) you can still see the loadout on loading and that means that you are at least aware of the possibility. it's similar to seeing the B4 commander in someone's loadout prior to the nerf(s) and then choosing a commander that didn't have the stuka bomb/recon.