I know that the M4 platform has a fair few options for customization.
So why not add them (not as attachments or COD-esque blueprints that change the stats or the tracers or the color). But like, say I wanted my M4 to look like the M16 out of the Vietnam era, could we add a prestige skin for it?
add an old Wooden RPK variant skin, M60 skin for the M249. (Just a few examples, they might not fit with the guns, but you can kinda get the point.)
IDK what skins and weapon attachments would work for the aesthetic and feel of the game without adding the weapon in as a separate gun.
I know that mastery and prestige camos are a big achievement in BBR, COD and the like, but I would find it more interesting to use a different gun variant, that is effectively the same thing, stat wise, but has different animations.