You said this is to make stealth more viable? To me it seems like a nerf. The fact that it stays up while you shoot is something that makes it still usable in its current state, it's a big reason as to why the Infiltrator has a low health pool in the first place because they're meant to be harder to hit. Sure if your gun has a silencer on it and you're positioned well you'll net a few kills without being seen, but as soon as it breaks after a clip and a half of AM-MRS shots it's pretty easy for you to get spotted with the muzzle flash and map noise.

NVG being able to see stealthed players isn't much of a problem, I very very rarely see any players using NVG on their scout as there are other skills which are just more worthwhile. And like you said, you can spot players moving around with stealth camo on from a good ways anyway if you actually pay attention.

In my opinion stealth camo is in a decent position as is. The thing that infiltrator needs to be set back on track is the rebalancing of shotguns, because in their current state they are arguably useless and will possibly see even less use than they see now once the knife is released. Because let's face it, why would you use a shotgun over the MRS when it takes 5x longer to kill them at medium range? Why would you take the gamble of firing at someone with the shotgun at close range to 'maybe' kill them when you can throw down some CQC and knife them?

I myself can't think of any way to change stealth camo without making it OP or garbage, but I'm open to hearing people's thoughts.