Rather than more ammo types for the 84mm recoilless rifles (which I wouldn’t be opposed to, though), I think the RPG and the M79 need the extra love.
The flexibility of the RPG-7 is, aside from the stupid-simple functionality, actually a major selling point for that weapon. There really are quite a few different types of ammo out there for the RPG-7, including thermobaric/fuel-air-explosive, fragmentation, and tandem-warhead HEAT with additional armor penetration. Because the warhead sticks outside of the launcher and therefore isn’t limited in size by the launcher tube, the weapon system is very open to modification and after-market munitions development…if you can dream it, build it, make it work, the RPG won’t mind.
As for the M79/G79, well, there are at least a few more options out there for 40mm shells compatible with the old thumper… The only addition I really, really want to see, though, is basically a giant shotgun shell. One shot, boom, blanket an area with pellets. Rifled barrel does mean the shot spreads out badly, limiting effective range/patterning compared to a shotgun’s smoothbore and choke, but that is the trade-off…one almighty shot up close, but you HAVE to be up close, then you gotta reload or swap to something else, reward/risk. Sneak up on a Hunter, blast the ever loving hell out of that backside…or, from a little further away, pepper a flock of Runners clustered around a radio, or a relay beacon? Just a different option from the HE round. Actually, I guess they could do a flare type round, as well. For distraction and visibility.
I know an underlying rule of sorts is to avoid anything being pay to win, but I don’t think that is an excuse to just let DLC items wither on the vine. They ought to get some love, just like the base game stuff does. Weapon skins (tiger striped M79, when?), ammo types, experimental ammo types, attachment reworking (1-4x, 4-8x scopes for the S21), damage rebalancing, maybe even remodeling. About that last part, ugh the Kotenok is incredibly awful…literally the absolute WORST looking ‘SVD-like’ I have EVER seen, in ANY game…and I’ve played Borderlands titles. I just—…I just can’t Kotenok.