I also write Z and z with a stroke. And then someone on Twitter suggested we should add it as an option. I don’t know why I didn’t think of it despite of writing it that way! It’s coming.
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.
They already are part of stylistic sets. So, for example, if you download a combination of 0 and 7 (regardless of which one), there are ss01-ss06 stylistic sets that encode other options in it.
The reason why we have a "font configurator" is because lot of terminals/IDEs/tools/OS, etc haven't got a full support for OpenType features. So we let users configure it as they like and it just works.
Oh that's good to know. Admittedly I didn't look too hard but I didn't see any indication that the salt tables were populated. Judging by the comments I may not be the only one.