I'm on a 2017 iMac. I can supplement some Mac things here. #ModeratorTeaming
For most of this, just replace "Ctrl" with "Cmd", and you'll be mostly good to go. On a Mac, however, you add Fn+F12, I believe, due to the "F12" being already mapped to a function in macOS (volume up).
Also, I don't think F12 makes the system used a server. I think it simply reestablishes the connection. That's at least what I got from the actual troubleshooting guide itself, as it doesn't mention that the system that presses F12 has to be the server in the beta4 troubleshooting guide.