The fully battened mainsail gets its shape from the sailcloth and mast bend primarily. Particularly in crosscut sails like we have. If you want to maximize draft, you minimize mast bend. Since we can't control halyard tension (damn hook) and since cunningham only works for about the first two battens (so leave it off in light breeze). All we can do in light breeze is lessen mainsheet tension. The battens are there primarily to support the excessive roach at the back of the sail. Sure, you can tighten or loosen them for conditions, but I've found over the years that lighter tension keeps me from having to pop the battens over as aggressively. Of course, there are cheating racers who keep the battens tight so that they can "WAVE" the boom for thrust in the really light stuff

but say...I was just popping the battens over! In light stuff, keeping things quiet to establish and maintain flow over the air foil is important so wasting time waving the mainsail about just keeps you from getting that flow established.
Putting the mainsheet in the back hole is a good strategy. Now that I think about it, I might even add a little extension bar and hook the mainsheet to the end of that bar...THAT would definitely put more camber into the sail. I noted when reefed that I had a more powerful (if shorter) mainsail because my sheet point was too far aft. Thanks for the thought.