add a repeatable custom blank field to weapon items as per vehicles

For every vehicle you can specify more custom fields (placed under the Crew field). Very useful to define passengers, cargo load, etc.
Would be nice to have the same feature for weapons, so you can define your own custom fields like caliber for fireweapons, recharging time for magical items, other attributes requirements (not only min. Str, some weapons have an Agi req.), specific Edge prerequisite, etc