Needless to say I called AppleCare and they were unable to square this circle. Neither the SSD clone or the Flash Drive install could be accessed in any way. It didn't matter which key combo I used to access RMode.

Rebooting into RMode began the whole process over again bringing me back to the message that my Computer OS needs to be reinstalled. This is the beginning of the install loop that can't be escaped.

Within 60 seconds of the red square flashing I was sent back to the screen informing me that the Computer OS needed to be Reinstalled. I then started the reinstall process which seemed to go ok until the process after the spinning globe, where the actual install begins, Apple logo over a progress bar, when approximately a minute in a red square flashed around the Apple Icon which lasted less than a second. Once in RMode I opened the Startup Security Utility and opted for the Medium setting and Bootable from External Drives. Prior to launching RMode, in order to erase and reformat the internal SSD, I made a full CCC clone of the 2018 MacBook's internal SSD using a Samsung SSD and I also created a bootable flash drive of macOS 10.13.6 just to be on the safe side. The OS that came with the computer was, of course, 10.13.6 This info is available in RMode from the Apple Menu 'About This Mac' which shows the version of the macOS install you're about to launch. I did not have Mojave on this system ever. Apple techs were clueless why this would be happening.

How to encrypt macbook pro hard drive