No, I won't add two settings! There are plenty of options in the config dialogs already.
My desire is to trim the number of options no increasing it.
Adding an option is the easiest way for the developer, but not for the user:)
It would be an offset from the default font OR a number specifying the size of the font.
(I could add some mumbo-jumbo to calculate the default with an offset, but I'm not sure I like the idea)
My preference is an offset, because if the user changes his/her default font - the tooltips will change automagically.