cloaking seems to be a no-go with the exception of gal-x and defiant since there seems to be so much pointless bickering about it. Another idea for feds is some tech from the delta quadrent from the devore imperium
it was used in the episode of startrek voyager called counterpoint where it blocked ships from scanning and targeting unless your sensors were tuned to pick it up plus the devere inspector gave the voyager crew the specs for it so its logical to assume they brought this back with them
anyway constructive feedback is welcome but please no more arguing
I think Baran's mercenary ship in "Gambit" Parts one and two had long range scan shielding, similar to what you are talking about. I would support having this added as an engineering consoel or device.
There are a number of stealth technologies (or other forms of deception) in the Star Trek universe, but only a handful of them matter since the rest are either wholly alien tech or designed for long range (and since the game deals with the extreme close range you can see the problem).
Put simply, cloaking is mainly Klingon and Romulan but I think that it would be reasonable to turn MES into either a console, device or some other method that allows it to be an option for Fed ships along similar lines that cloaking is for Klingon ones (and will be for Romulans when the time comes).
EDIT: Also, there is a difference between running a few scans for certain energy signatures and bringing back functioning technology. If you really look at it, Voyager didn't bring back a lot of technology with them, mostly just charts, stellar and species information. Of course there are a few notable exceptions but still you can't really say that they have an operational knowledge of something just because it was in one episode and they got some scans.....