Simple solution to sliding with shotguns is to lock the view of the player to the direction they are sliding and only allow up to 90 degrees of turning from where they are sliding to with a slower turn sensitivity. It would prevent players from sliding and being able to do a complete 180 while sliding to shoot a target behind them. It would also give players opportunities to out manoeuvre the sliding enemy. Then if it can be done only to PvP I'd have it so consecutive shotgun blasts would gain more spread if you didn't give the shotgun a second to go back to normal. It would balance out the fact there is no consequences to spamming shotgun shots. Felwinters probably does need some touching in the range department so it isn't widely better than any other shotty.