I was looking around and cannot seem to find a mod that increases the number of parts for the weapon generator to use, there are some for monsters and plants, but none for weapons.
The monster and plant generators probably work in a similar way -- e.g., they're rigged up to have specific "archetypes" such as bipeds, quadrupeds, etc, that select their parts from a certain selection; weapons effectively do the same thing, but with their own respective sets of parts. You could probably look at the structure of those mods and see how they function, but instead of implementing more plant or monster parts, you could design weapon parts instead. One of the best ways to learn how to make things is to closely study things that have already been made!
