This method seems like it would work with the various startle responses and the convulsing fist would hold the weapon more securely. The same reason I very much like Massad Ayoob's stressfire revolver reload. Unlike the stressfire revolver reload (I would have to do some serious dry work to confirm or deny this gut reaction) it would be a lot of work to break down enough to effectively teach. It looks like so ething that you have developdd into a workable solution, and I like the security it would provide. Not sure for me and mine it would be worth switching to.
pat