I just received my RATGDO board and have tried flashing with the ESPHome SW. The blue LED on the board briefly flashes when I plug in the USB cable and then stays off. The Web flashing tool states that no device is detected. I have tried 3 different cables with the same results.
After trying multiple USB cables I was able to successfully flash ESPhome and everything looks good. Next step is to wire it in to the main garage door opener.