Spend credits at the weapon vendor to unlock weapon blueprints, higher tiers and hopefully even custom upgrades (like a long range sight for L3 sniper).
Pick a few of your blueprints as active so they appear to you on the fabricator with Materia costs according to rarity/upgrades. (Number of slots can be limited to anything, even locked behind credits/level/other type of progression)
Craft your favorite gun whenever you need it. Or when your teammates want it too. Just don't burn all of the ship's Materia on this.
#Custom weapon blueprints for on-foot weapons to craft in mission
velvet breach
plush rapids
I came here to suggest a very similar fix. I think the only major difference was I thinking that salvaged weapons could reward credits like any other salvage, and that the cost to buy from the shop should be the same as the salvage cost. However, frankly I like this better! 👍
I think a great way to do this could be to allow each player in a game to unlock 1-3 slots that they each add to the ship's available arsenal when they join, so everyone can support their own personal preferences, but also you end up seeing others' preferred loadouts and getting to try those out. 👍