Any extension's set up configuration connected to the MRG2 set up is stored in a non-volatile memory of the MRG2 master controller. Therefore the extension device(s) need to remain plugged into their given (original connected) MRG2 socket..
https://www.midi-hardware.com/?section=prod_info&product=MRG2You can easily copy MRG2 settings this way: connect source MRG2 MIDI OUT
to destination MRG2 MIDI IN, and then connect the Keypad to the source MRG2,
and enter
#978. After about 2s all user settings will be copied to the
destination MRG2.
Esp useful to be able to duplicate a setup.
Rgds,
Ed