A bit belated but on last week's Livestream where Matt was running on GWE he did explain some of the Ctrl functions related to cabs. Ctrl 0 puts you back in the cab you were in. Ctrl + or Ctrl - puts you in the cab you were previously in when in cab. Useful if you have swapped ends and found the brakes remain on because you didn't put the Train Brake in Shutdown in the other cab!