Ring Floodlight Cam Pro Wired - Rectangular Horizontal JBox Mount Use Adapter?

I purchased a Ring Floodlight Cam Pro the other week, however when I went to install it the Ring would NOT mount to the rectangular metal junction box installed in the stone wall of my garage. I called an electrician, as that was the ONLY answer I got from Ring Support the first time I called. Electrician came out, looked over the problem and said there was nothing he could do as he was not a stone mason. He was sure that Ring should have an adapter plate to mate the Ring Floodlight cams to rectangular steel junction boxes as the rectangular junction boxes are extremely common, especially in older homes.  I called back into Ring today looking for information on an adapter plate, but all I could find was one for the rectangular adapter plate for the Spotlight cam. The Ring CSR told me I needed to switch to a Ring Spotlight Cam; I had to inform him that Ring recommended the Floodlight Cam for large driveways, and that the Spotlight Cam simply could not cover a large driveway. Next suggestion was to relocate the Floodlight camera to an other than optimal location, only option was an area 5 ft off the ground which would not allow for full coverage and would expose the camera to vandalism and/or theft. Next suggestion from the Ring CSR was to simply cut out a larger hole through the river rock and to mount a round junction box; my electrician is not a stone mason, and neither am I, so not an option. The CSR had no further suggestions other than to wait to see if Ring puts out an adapter... I simply cannot believe that as long as the Floodlight Cam have been out, that Ring has not addressed this issue. And since they released the rectangular mount plate for the Spotlight Cam, they are obviously very well aware that rectangular junction boxes exist, and are in fairly widespread use. I would really like to mount this camera, and install a Ring alarm, but if I can't find a solution I'm coming to have to look elsewhere. Has anyone encountered this issue and could up with a workable solution?