Actually there is a similar issue with Chafitz Modular Game System as well:

The Grünfeld/Grünfeld-S module is supposed for openings, Morphy/Sandy/Steinitz/Steinitz-4 for middle game and Capablanca/Capablanca-S for end game.

https://www.schach-computer.info/wik...ar_Game_System

According to http://chess-computer.blogspot.com/2...phycapabl.html the change of the modules is performed like this:

1. Press RANK key
2. Switch from ON to MEM
3. Change module
4. Switch back from MEM to ON

Best regards
Markus