if we ever added em i would only seeing it viable as an objective/pickup weapon. no plans atm though
my personal take:
fuse-lit early hand cannon thing - 1 tap heads, 1 shot chest on anything lower than heavy, non fatal shots ragdoll. 2-3 shots total, when you click lmb you light it, and it goes off somewhere between 3-5 seconds randomly. garbage sway too so you just have to track the target, and a big audio/visual indicator (smoke/sparks) that you're about to get yeeted. also if you drop the gun (melee/projectile damage received) during the fuse burn animation it'd still be active, so start running.
edit: ridiculous proj speed and sh*t accuracy too, just to spice things up