I think the best way to handle this is just to tweak the slot values in the json files on a case by case basis for weapons that seem overloaded. I think most of them are actually ok as-is; most weapons only allow one mod in any particular slot anyway, so even if a gun has a lot of mods, theyāre not being placed un-realistically. Mods are also already restricted in what types of guns theyāre compatible with. Even though a pistol has an underbarrel slot, it canāt use a M203 grenade launcher, only an underbarrel laser sight.
Also, a lot of the mods are for things that replace pieces of the original gun, like conversion kits or replacement stocks. We should actually think about adding some flags for mods that donāt actually add their weight or volume to guns theyāre attached to (since they replace original pieces of the gun, which get removed). This would also let us add mods like collapsing stocks, that reduce a gunās volume.
As for the original topic, I like the idea of just having a +x addition to the name in the hud. Itās small, itās informative, and itās cool in an old D&D sort of way.