I have used a double over lap grip since early on.
"So to summarize, you've discovered that an important dimension to wrist cocking is to have trail wrist flexion? Or, is it that you don't believe that your wrist is flexible enough to have ideal wrist flexion?"
I know trail wrist flexion at impact is needed... so no discovery there.
A little while back Ham posted some stills comparing my swing to Dustin Johnson...one of which compared my impact vs his. I saw immediately my wrist bent less than his. Around the same time Allen posted his bowing the lead wrist thread about the impact snap aid / hands more forward, improving his impact position.
So that just got me thinking about the whole thing...I knew straight up I didn't want to start practicing with something like the impact snap because I just didn't like the manipulation and the straightening of the trail arm I saw in all the demos of the device. But thanks to Ham, I felt I could improve my impact position. And then I watched the video of Sadlowski and his talk of supple wrists being a requirement, and I said "there's something I can work on without changing my swing!"
So for me the "only way out" was to improve the flexibility and strength of my trail wrist. In a real swing, with an early set of the wrists, and the force of loading in transition - there is more of an opportunity to have more trail wrist bend if the trail wrist can bend more - is more flexible.
So yes to your second question, I believe there is an opportunity for me to improve the flexibility in my trail wrist and this will help me achieve a better impact position. It also doesn't conflict with my whole "Bertholy mindset" of training for active retention and involuntary release.
Never quit til you have a swing you'll never forget!