Hey all. I'm pretty familiar with Mojave's ins and outs. Based on what I'm seeing, the only way to get keyboard and mouse going again is go to follow the original steps above while physically on the computer. The only other way we've seen around this is to use Apple Remote Desktop (ARD) and/or VPN to get into the Mac, since it doesn't require a 3rd-party authentication.
Customer support service by UserEcho