no, it's unfortunately not possible. The U2F implementation is done on a different firmware version requiring attestation keys that are installed at factory personalization time
Seems like a good project, keep it up and I hope these smart cards can get made!

well the cards are made and actually quite popular at TNABC

I got one yesterday in the mail. can't get any computer to even recognize it. how do i tell if it's dead or something? spent like 2 hours with it, waste of time so far...

Edit - two windows 7 64-bit - even tried old drivers etc. nothing seems to work ... Windows device manager sees nothing at all, no matter what usb port i try. 1 Dell laptop and 1 ASUS home built desktop.
ps i tried on linux mint as well, but i didn't get very far at all before giving up there too. (Older laptop).
thanks for any help.