Consider the above tutorial. I would suggest doing what spotter says by mounting underneath but using the above cable tie technique. No residue/ mess and guaranteed not to fail.
I know the 3M stickies are really strong, but mounted underneath with the full gopro's weight pulling on it, security would weigh on my mind.
Strip of metal or plastic/acrylic etc sized to span between the slats and attached to them via zip ties, p clips or whatever with the qr buckle thing stuck to it? Would allow you to use the full area of the adhesive pad which I don’t think sticking directly to the flats would?
https://www.youtube.com/watch?v=9sVUW4nQoGs
Consider the above tutorial. I would suggest doing what spotter says by mounting underneath but using the above cable tie technique. No residue/ mess and guaranteed not to fail.
I know the 3M stickies are really strong, but mounted underneath with the full gopro's weight pulling on it, security would weigh on my mind.