Actually, the design and concept is Fred Smith's at Bullberry/Woodsmith - VVCG is his ex crew from about 5 years ago - copied it. Yes, it works very well, and it can be used with Pachy and single screw mounting TC forends, without modifications to the forend, so you don't have to buy custom. I've posted before how to do it. I think Fred is charging $6 for the bar with screws (specify stand-off spacing), little to dish out to try it out for yourself. All my barrels wear them BTW.
Ladobe