I saw this, and the comment below asking why there are different versions of e.g. 0 and 7. Saw the variant picker on your site, and I can't help but wonder:
Do you have any plans to add the different variants in as stylistic alternates (SALTn tables)? This is how FontFont encoded two styles of numbers and other various symbols into a single OpenType font. With FF Zwo I like some of the alternates but not others and this lets me choose.