Warlocks have Tranversive Steps and 3 chest pieces with these perks (Starfire Protocol, Alchemist Raiments and Purifier Robes), Titans have 2 chest pieces (The Armamentarium and Twilight Garrison), Hunters however have [u][b]NONE[/b][/u]. All other exotics specify the type of weapon that will have extra heavy ammo and allow to carry less than these generic weapon type perks (example: 6 Ghorn rockets vs 7 with one of these exotics), and this perk also increase the amount of ammo for the Sleeper Stimulant from 9 to 12 (and sword ammo by 1-2, irrelevant for swords). I don't expect you to create a Hunter exotic this late, but at least have this in consideration for Destiny 2.
Let's think where 1 rocket or 20 me shots would come in handy. Raid? Not in WotM. 20k damage is nothing in the long run. Nightfall? Odd are you either melt the boss with supers or you peck away 1 rocket at a time while always killing every single add before damaging boss which takes well over five minutes. All those heavy boosts are useless in pvp. Heroic strikes and more or less the same.