Why do they sell these?
Can you use one of the knobs with the lag screw on the back or as I interpret the code, a long bolt through structural wood with a nut/washer on the back.

Incoming overhead cable is about 40ft. 6-112(6) says bolted but is a lag screw considered a bolt?

Im upgrading a 100A to 200A and don't want to rip the wall open unless absolutely necessary. I know the lag type insulator would hold but if they are not allowed by code, why do all the suppliers have lots on the shelves?