Fusions are just barely under shotguns in pvp any buff would probably be too much. However they could probably give em a pve buff especially telesto. Maybe damage fall-off against pve enemies increased by 25% because right now thanks to the range boost shotguns get in pve they can go all the way up to adaptive fusion rifle range and aren't too far from precision and high impact fusions. Which with shotguns hitting harder and generally having a few more rounds than a fusion does it tends to make shotguns better. As for Telesto I would increase Telesto's damage by 25%. The thing hits like a wet noodle but needs to somehow get MULTIKILLS to get the perk active which the perk is like the only good thing about the gun in pve.