This is a very cool concept but I do have some suggestions on the implementations. Here's a list:
Announce when new weapons or weapon parts become available. Time it with the next time you would interact with the weaponsmith.
I would like to test the weapons with actual opponents and not just against the dummy. At least give both dummy and actual opponent (like in Spar mode) as options.
Not sure if this would be too-handholdy but an explanation for how the mass and size stats affect the weapon would be nice. The trial and error is sort of fun but it would be nice to have an insy-bitsy tutorial.
The last gripe I got is the way the stats (Size & Mass) reset every time I test the weapon with the dummy. PLEASE change that.
REMEMBER DEVS: Everyone loves this game and we are all thankful for all the blood, sweat, and tears you have all devoted to bringing this project forward. I have faith in you and I hope that faith is not misplaced. Much love <3