I don't see why naming is so important, but I vote for STEMist, the only one out of the three that doesn't end in ist is mathematician.

Also a simple UI would be great, I kind of hate side bars and boxes everywhere.

Also STEMizen from citizen is the first thing that came to mind, but that's because I saw STEM everywhere.

But I'm adding rather than focusing, I don't like 80% of the poll names, so systemic is the most likely I'd pick, it sounds interesting and related to the topic and not related to the technology.