I don't have a real printer now. I have a label printer installed only able to print labels 6-24mm wide. When I want to create a new worksheet I can only select paper formats my printer is able to print which is maximum 24mm wide. You dont' produce nice results with this narrow pages.
Of course, the selection of a paper format should be independant of what the currently installed printer(s) are/is able to print. You should be able to choose all the international, north american and japanese paper formats. (BTW, are there russian formats too?) One may never physically print worksheets. Another user may install the appropriate printer later on - specially with USB. Smath Studio should work nonetheless.