For Delphi / RAD Studio version 12.3, the original solution provided by Jim:
C:\> getitcmd -i=fmxlinux-12-1.78
works "out of the box" with no issues !! ( --> no "patch" needed as in 12.2 )
You can use this solution to get "FMX Linux" until they reach a final agreement with Kryukov's state ...