My RV-12 exhibited the same behavior during power on stalls. It flew straight, regardless of flap position in slow speed flight.
I never really figured out or mastered that right wing drop at power on stall, as I had a lot of right rudder kicked in just to keep the plane on course. My instructor had no problem with it, nor did my fellow RV-12 friend who also flew my plane. Nose just dropped normally, for them, wings level. More experience, more coordination with hands and feet?
There is a normal P effect from the rotation of the prop providing the left wing with more lift than the right wing, therefore the right wing will stall first, it's pretty normal. Some plane wing designs mess up the laminar flow on the leading edge of the left wing such that the plane exhibits equal lift from both wings near stall speed. I don't know if the RV-12 has this engineered into their wing design or not.
I chalked it up as a lack of experience / coordination on my part, because I went and flew a PA28 150, and it's behavior during a power on stall was down right docile, child's play.
Maybe try it a few more times and see if you can get the coordination? My wings buffeted at the root for quite some time before my plane would actually stall and the right wing and nose would drop very quickly.
Or let someone else with an RV-12 fly it to confirm?
i did have proper seals installed.