I have purchased two D065 lens plates for the foot of the 70x200 lens. I use one on my 70x200 and one on my 100x500. They fit perfectly. The machined stud fits into the extra 1/4†hole on the foot so there’s no twisting of the plate on the foot. The machining is very good as are the fit and finish. I highly recommend this plate for the foot of both the Canon 100x500 and the 70x200 lenses.
I have also used this plate on camera cages on the Canon R5 so I could put a vertical plate on the side of the cage. This allowed me to use the camera on a gimbal mount. This setup provided clearance so that the tilt screen would work unimpeded. This plate works very well for that application. With the machined stud is placed in a 1/4†hole, once again there’s no twisting of the plate on the cage