Suggestion: let Item Lab swap the main/secondary weapons of a multi-weapon around, for a fee.
Reason: primary cosmetic.
I am building a Rifle+Launcher multi-weapon, but I have weapon camos for both rifles and launchers that I like, and would love it if I can make the decision to show the rifle as the base today, then the launcher as the base weapon maybe two days later.
The easiest way to implement it would be adding an Item Lab option to swap the primary/secondary weapons of an already existing multi-weapon, while keeping the enhancement level, autmentation, and potentials on the multi-weapon.
Concern #1: becomes a way to "inherit" enhancement and augmentations to completely new weapon types
One concern is that it would allow us to "inherit" enhancement and augmentations to other weapon types, for example I could have a Rod+Talis +40 with all the best augments, and when Bouncer comes out, I could just multi-weapon a pair of Jet Boots to make a Rod+Jet Boots, then swap it to Jet Boots+Rod, and then multi-weapon again to make a Jet Boots+Soaring Blades.
But this is already partially possible because we can already overwrite the secondary weapon of a multi-weapon. And by inheriting this way, the original multi-weapon is completely destroyed anyways.
The restriction of requiring the same weapon series also means it's not possible to inherit augments from a lower rarity weapon, because higher rarity weapons will be from different series.
Concern #2: it could be used to try out new classes cheaply.
So instead of making a whole new Jet Boots+Soaring Blade +40 and augment them, I could take my existing Rod+Talis +40 and multi it to Rod+JB, the swap to JB+Rod and multi it into JB+SB. Then if I don't like it, I could again do all that in reverse and go back to Rod+Talis.
But this isn't really a problem, because I still need to have JB and SB from the same weapon series as my Rod, and I would still consume them in the process, plus another set of Rod and Talis if I want to go back.
Benefit #1: it vastly lowers the cost of trying out different multi-weapon combinations
This means I could easily make a Rifle+Launcher, then go to Rifle+Bow, try it and decide I don't like it, then swap it around to Bow+Rifle and go to Bow+Launcher, for example.
Don't Do #1: don't make the cost prohibitive, such as requiring N-Ex-Cubes.
If it requires N-Ex-Cubes to swap, then it becomes undesirable to swap it just for the cosmetic look. I think at most a significant money and ore cost would be enough, such as requiring 400,000 N-MST and 50 Photon Quartz.
Yes I just want to be able to walk around with a sassy rifle and every now and then have my Bananan Launcher on my back for a couple of days.