I think at least three devices ("several") are now designed and manufactured to specs, LOVELWLG, and so we are now, at last, just where you want us to be: holding at least three little "engines" that do work and can be improved upon. And the first improvement, stunningly right on the heels of those device-design successes seems to be new polymer for those devices that can just be subbed in for the older polymer - either across the board for all devices or for certain special devices in which that intensity of infrared light has been the high-end challenge, I don't know.
But I get it if you don't believe it after all you've got in this. I'd be jaded as hell, too.