MIU Weapon Interface + Sniper Rifle

[wholton 1]

So, one of my players wants to attach a sniper rifle to his shoulder via a MIU Weapon Interface. Attaching Basic and even Heavy weapons via this thing seems possible given the wording, but abnormally strong... and given the long barrel on a rifle, it seems odd to allow it to be shoulder mounted. I've looked up and found FAQ entries that will at least put a damper on Heavy weapons (they must be carted), and have found other opinions that shoulder mounted Basic weapons apply subtlety penalties and could be forced to be compact.

 

What are your rules and restrictions regarding this? I realize the penalty to subtlety and forcing Compact will balance things a bit, but I'm afraid to give it the okay and have the Tech-Priest in the warband outdo everyone else in every department (all of the armor enhancements + full-action aim into free-action sniper rifle means he'll be abnormally strong in combat, and he is already a face / skill monkey via his role).

[MijRai 196]

I'd flat-out not allow Basic weapons to be shoulder mounted on anything lighter than power-armor.  Pistol-sized and smaller would be my limitation.  The sniper in my game got a needle-pistol mounted to his shoulder for use with his MIU.  Even a 'compact' weapon of the Basic class would have a foot-long barrel or so on top of the receiver, stock, etc, which would get in the way for sure.  Not to mention weight.