USAAC also employed "live" targets
In addition to the P-63 "Pinball" variants, the US military also had radio controlled drone planes, such as the OQ-2 and TDD-1, although drones were mostly used for training flak gunners. Other nations, not being as rich or as heavily industrialized as the USA, only had target drogues.
All of these planes would be interesting historical projects.
The P-63 Pinball would be the easiest to model, since all you need to do is alter the FM and DM for the existing P-63 and add a special "damage effect" which makes a light on the aircraft flash when it is hit. But, unless you alter the game to include loadouts for frangible bullets, the P-63 Pinball variant would be problematic in multiplayer since it would be virtually indestructible.
Another way to model the "Pinball" would be to have an option within the FMB or QMB to make certain aircraft indestructible by gunfire. Ignoring the lack of the flashing light to indicate bullet hits, a standard P-63 with an orange paint job, set to "Indestructible," and with an "Empty" gun loadout could substitute.
Drones would require new models and would essentially be new aircraft. But, if you're wanting to fight against lightly armored, small, maneuverable foes, just queue up a batch of Rookie Ki-27, A5M2, or Ki-43.