So, it looks like the Impersonation State is missing the NFB tag. The NFB tag is on the deployment skill, but that doesn't apply to Cybermask as best I can tell. So without that missing NFB tag on the Impersonation State, a Malignos with Cybermask could still benefit from Mimetism right? I don't think it should work, but I've been wrong about a lot and don't personally agree with a handful of "rulings", but somebody please set me straight here.
NFB is not on the states, but on skill, equipment and programs. It says the activation of any hacking Program with NFB (Cybermask the program has NFB) will cancel any other Skills with NFB until the effects of the new Etc. is cancelled. So no, you can't stack Cybermask with Mimetism. Also, a previous FAQ said you only regain Mimetism on the next Order/ARO after you have cancelled Cybermask's effect of IMP State but I'm not sure if it applies to N4.
This has been integrated with the last line you quoted. "Therefore, when using an Order, a Trooper will only be allowed to have one active piece of Equipment, Hacking Program, or Special Skill with the Negative Feedback Trait." During a single order, you can use a single NFB perk
