I've heard Larry Vetterman was working with someone experimenting with the VG's. I was and could still contaplate putting them on mine......if I ever get close to finishing
From what I believe if they were installed the best place to put them would be in front of the ailerons.
Especially on the RV-6 or any of these while the wing drops from the stall the VG's would at least give better aileron control for roll effect.
Obviously stop the stall and opposite rudder as needed but the VG's over the aileron area would give faster airflow over that part of the wing to give roll recovery sooner. Or you might have roll control while the inboard part of the wing stalls.
I have not flown an RV with them but the one I have flown did drop off quite fast during the stall.
comments encouraged and appreciated
........as long as you can back up your info