Ah !!! VALUES !!!
Andro 4.4.2, same.
kernel 3.4.0-g0c47a10, root@abm022 #1, SMP PREEMPT, you probably forgot the last part, or used a tool that does not provide it.
I don't have HW version in my phone (this is probably my ROM) - I know what it looks like, I had it on my previous phone. The thing that most looks like your HW version has for me the value "002"
ROM 1.54.1020.10 CL325784
Before update, I had ROM 1.54.1020.5
So, we do not have the same hardware (my HW is ver 01 or 002), and ... completely different ROM.
Would need you exact kernel version. If we have the same kernel, and your phone can do UMS, then, it's just a matter of messing stuff in /system (the two guilines I wuoted above may work). If we do not have the same kernel ... I won't even try those tricks: my kernel probably can't do it.
If TWRP is available from sources ... I will ask a friend to rebuild it for me ... including the stuff required for UMS (he can do it, 100% certain). Once he does the kernel, the rest is peace of cake in a recovery ROM.
Don't flash again. Just give me your kernel version. If the kernel is the same for your two ROMs, then, your two roms can have UMS; just a matter of tweaking the right things at the right place; in short, find the APK or system script that handles it, and copy it to the other ROM.
I would be interessed in downloading your two ROMs. Especially if one can do UMS, but not the other one. Whether they share the same kernel or not. I just don't know if I would have the patience to push them in my phone to see things by myself; but if I took the time, I may be able to extract the relevant bit of code, and try to copy it to my ROM. Issue is that I have only one phone; and it would mean ... spending 2 days on it, and not be able to use GSM at all for 2 or 3 days (no phone, no SMS). It would be interesting, but I am not sure I would really take time and efforts to do it.
---------- Post added at 07:54 PM ---------- Previous post was at 07:37 PM ----------
The kernel source for this is available on HTCDev, as it is with all the M8 variants. None of the kernels (as-is) will get UMS working in recovery, though.
The Sprint variant uses a different defconfig than the GSM version, so perhaps whatever is different between the two is what is making the difference. It's also possibly a userspace difference, since the CDMA carriers like/need to customize the ROM a bit more for everything to work.
I'm just surprised that not all of the M8 Sense ROMs include the Disk Drive option.