41CL - how to activate 9xxx configurations

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Last week I received my 41CL (V5 incl. time clone) and I am thrilled. I have worked through the available documentation and everything is pretty clear. The system is now updated to the latest rom_versions (21/02/2019) - it took just 20 minutes in CPONLY mode - and everything works as expected.

However, I have problems with loading predefined 9xxx configurations. In order to load i.e. 9MTH I need to have the extreme functions (YFNX) enabled at page 7. Whatever I do to load the 9MTH configuration leads to a configuration error, because the extreme functions are configured twice. Do I have to unprotect YFNX first ?

Is there someone who would let me know the easiest way of activating a predefined 9xx configuration after Memory Lost ?