For anyone wondering about the general SD card issues on mostly dualboot devices (for some even after going to Windows only, but all were previously dualboot), see: http://forum.chuwi.com/forum.php?mod=viewthread&tid=3593
Existing "flawed" dualboot designs as far as integrated card-reader support also "flawed" in case of competitors, are not a reason to stop creating new hopefully better models. Because repairs don't generate revenue. And without revenue, there won't be a forum or a customer service to complain to. No one wants Chuwi to reach "chapter 11".