Prevent hardware and library examples from showing in the Sketchbook menu
Looking at the code it is scanning all folders and there is no option to change that behavior. Also looking at the code, it looks like it dumps them into a sub-menu, hiding them away a little further, if the folder is named anything except "examples", which could be an alternative option for you.

The final option would be to fork your own version and come up with some exclusion logic, maybe with some kind of ".ignore" kind of logic where you can specify folders to exclude form the menu.