Lehet két és fél hónap elég volt rá (és mintha a Mozilla eleve támogatójuk lenne) :)
"Sep 14, 2015 - Our cross signature is not yet in place, however this certificate is fully functional for clients with the ISRG root in their trust store. When we are cross signed, approximately a month from now, our certificates will work just about anywhere while our root propagates. We submitted initial applications to the root programs for Mozilla, Google, Microsoft, and Apple today."
Forrás