Thanks for forcing me to think again

Figured it out finally... and ended up with this:
menu_item :main :Invert Screen :nickel_setting :toggle :invert
menu_item :reader :Invert Screen :nickel_setting :toggle :invert
menu_item :main :Portrait/landscape :nickel_orientation :swap
menu_item :reader :Portrait/landscape :nickel_orientation :swap
And it worked...