I see you’ve given up on the idea for now, but I’ll give my thoughts for next time. I have wide gunnels and the tracks on the gunnels are great, but I have lots of area for reinforcement underneath.
MY old boat had skinny gunnels and I mounted tracks on the decks and used pedestals. It was a great setup, and when they weren’t in use I put the inserts in the tracks and it was a very clean install. That’s the way I’d go if I where you.