Properties that can be used as a pre-select (Fast Match)

Dumb question time on usage of pre-select property for a GKC.
Can I use as a pre-select property Prototype == (say) “aircap”?
Or maybe if I add to that prototype, a marker trait with the same text? (mission = aircap)?

Protoypes themselves do not create any properties, you would need to add a marker trait as you suggest. Any properties can be used as Fast Match properties.