It should also work with Vivaldi (From the makers of Opera) and tries to make a more modern Opera 12. Vivaldi uses chrome extensions. I still see some people using Opera and they never switched to Vivaldi.
That happens to be the very browser I'm using now, but Vivaldi support doesn't surprise me, given that it's built on Chromium. I love Safari and will continue to use it every day, but the previous (?) lack of U2F support was (is?) a drag.
