Where to put config var to make it visible in editor preferences

Title says it all, where do I have to put in the variable to expose it to the editor preferences?
Since I want it project independent, putting it inside the UEditorLoadingSavingSettings.h is out of question. Also because of the fact that the variable
needs to be loaded before the project selection, I can’t put it there.
However I was able to edit and see the variable inside the preferences!

I tried the EditorSettings.h but when I compile it and check the preferences, it won’t appear in the Loading & Saving tab nor anywhere else, despite
the UPROPERTY(EditAnywhere, config, Category=Startup) specifiers.

Any ideas? I’m still very new to the engine modifications and C++ programming in general^^

  • Trinity