I think this is a big, current issue that’s faced by a lot of people, especially veterans or longer time players who generally end up with duplicates of special editions (either through grinding or purchasing) or others who were unfortunate enough (like me) to end up with a shitty unwanted loadout from the Javelin RNG/ranked cases and what not.
I suggest a re-work to the weapon kits, alongside making them more obtainable outside of arsenal crates, perhaps either by purchase or by drops similar to equipment cases. The idea is to make it so weapon kits can be used both during crafting to choose specific weapon loadouts for the merc you want, but to also re-roll (at a reduced cost, obviously) an existing loadout card of the same merc to obtain a different loadout either with the same weapon or from one of the other 8 loadouts (if it could be made to eliminate the previous loadout from the drop to avoid any RNG shenanigans that would be awesome!). I think that this would give weapon kits a bit more collective value, but the other main essential point to be made here is to increase the methods in which players can obtain weapon kits so they become more widely useable.
This solves both the issue of people who have ended up with unwanted/duplicate special editions which can’t be recycled as well as re-works and makes weapon kits more desirable and obtainable. Two birds, one stone, what do you think?