According to this post on the chuwi forum by an admin, it wouldn’t be possible to upgrade the current hi12’s to dual boot.
Newer one http://forum.chuwi.com/forum.php?mod=viewthread&tid=139#lastpost
Chuwi Forum Admin say he don’t know.
on other unofficial posts they say it is possible and android informations are already in the current bios.
What I've used and what I've got:
TECLAST X98 AIR 3G, TECLAST X98 AIR II, TECLAST X98 PRO,CHUWI HI8, CHUWI HI12, CUBE I9