I suspect that JP4/Raketen ambush bonus is bugged; i.e., I think that these units retain their ambush bonus INFINITELY and for all shots they fire (even without camo)
What I am referring to is bug #1 from https://www.coh2.org/topic/48300/various-bugs-commandos-artillery-ninjas
Commandos ambush bonus is probably a copy-paste from raketen/jp4; since commandos are bugged, it is very likely that these units are also bugged as well.
(I haven't reported this as a bug yet, because I haven't verified it yet).
Well, I'm pretty sure it can't be exactly a copy of those ones (and I mean exactly), because Raketen's supposed to gain shittons of penetration. If the Mandos had that, they'd of course be killing tanks.