Although, in that frame of reference, I'd love Ag mods to reduce drop-off by 1% on shotguns. And sniper mods to put them in the next narrower spread category (with combat-shotty spread being turned to bullet-style targetting, or rail-gun-like but with drop-off). The first one's easy, the second is fiddly.
The first one is also probably over-powered. An extra 1-4 squares of scouting range is pretty massive, the extra damage is also a huge bonus. Fairly situational (needs a big room or corridor to really shine), but still very handy.
The second is simply so a gun can be modded. A (9d3)x2 DB-shotty with less spread isn't really that good, neither's a single-fire with a CS's fire cone. A CS or AS with a bullet-fire or rail-gun-fire-with-drop-off might be pretty sweet though. It just feels stupid dumping an S-mod because you're not a whizz-kid. Any better suggestions?