And yet a third party app works flawlessly... I understand their points and they are not raised here for the first time, but I still do not buy it. The DFR and DFB could easily include a "device driver" - as easy as work together with UAPP - and finally get over it.
While I agree with you that Audioquest should be doing more (and especially should
have done much more), I am not entirely sure that it is possible to solve the issue satisfactorily. One simple option would be to set the reported volume at max, so that Android would register the correct max value as well. This might leave many users with IEMs at ear-splitting minimum volume though. As for drivers, unfortunately Android is heavily sandboxed, and there is no simple way to install an app ("driver") on your phone that will change the way other apps send audio out, if that's what you meant. As far as I know the modification has to be made at a system level, and that means OEM or ROM maker. Single apps like UAPP can implement modified drivers, but only inside the app itself.
There are of course many other DACs working well on Android, why? Well, some have a physical volume control, some have a gain switch, but for the remaining ones my theory (based mostly on other people's reviews and notes, mind you) is that other DACs might have less volume variation between min and max, which means that they can safely report max volume to Android without going too high for IEMs at min volume (and actually some do: many portable DAC reviews mention volume too high at min-low gain for sensitive monitors - see Cayin C5DAC for example).
Since the DF is supposed to be firmware upgradeable, I would think that there might be some way to solve this. If the upgrade is able to set the reported max value, for example, they could at the very least release two separate updates, one to set the max value at what currently is, and another one to set it at the actual max value. This would mean reflashing the correct firmware every time you want to switch (as a sort of software gain switch), i.e. a real pain in the a**, but at least it would give us a choice. However I am not sure that a big-ish company such as AQ would go for such a hacky solution (I can only imagine the emails that their support would receive after unsuspecting users flashed the wrong upgrade). So I can sort of understand that it might take a while to figure out a good solution, what I cannot excuse is the total lack of communication on their part. As far as we know, they might not even be working on it, honestly.
