Great work on this.
Any way to get exFAT working on this? It seems to be working fine on the version from Dees_Troy (my card is formatted exFAT).
The tree Dees_Troy put up is here: https://github.com/TeamWin/android_device_htc_m8_whl
(I'm sure you already know this)
I also caught him on IRC yesterday and he said he'd look at any errors in the source tomorrow, as I was having issues building with it as-is. With all the additional updates you had to make, it's no wonder!