One of the annoying things for me about the Duviri weapon selection is that I see many of the worst weapons regularly. I have most weapons, so the forced inclusion of unowned choices has a small pool to pick from. And many of that small pool were weapons I had but just didn't enjoy, so I got rid of them.
The situation forces a strange option. If I want to have it not show up as much, I can acquire the weapon. So I would go through whatever effort is required and pay for a weapon slot just to not use the weapon. Feels like a cash grab.
A quick and easy fix would be to remove the mastered weapons from the list of unowned options. Then if there is some crappy weapon you keep seeing, you can acquire it, master it, and then sell it (clearing up the weapon slot, at least).