There are certain modules that limit you to only having one for a given weapon type equipped. While similar to Exclusive Category in function, this is specific to weapon types.
When adding to this list, please keep it alphabetical for ease of use.
Text Launcher Shotgun Sniper Sub Weapon
{ "type": "PROPERTY_CONSTRAINT_SCHEMA", "constraints": { "type_constraint": "_txt", "allowed_values": [ "Launcher", "Shotgun", "Sniper" ] } }