I am a kind of guy who is happy to improve his character even a little, so if I know myself I'd hoard 5 mods for mortuary to get that combat pistol, mod it and get reasonably stronger. I actually always visit the mortuary and never died there. If it's not a big deal, because it's so late, so why not? It would make some people happy (like me) and it wouldn't hurt balance whatsoever.
About Armory/Deimos I don't actually agree. It's up to RNG if you get something suitable for you or not, it always was in most of the games/challenges. If you don't like it, get Scavenger trait.
And, funny, I find rather assault shotgun more useful than plasma one :D Shotguns are all about corner shooting.