All you guys need to do to have UAPP play in high res (without enabling hi-res in UAPP) is
1. Go to Settings->Android Audio
2. Enable "Play through Android"
3. Set "Android sample rate" to "Variable".
In fact, UAPP is very instructive in this regard as to the benefits of HiBy DTA. It is simplicity itself for an Android app to throw unprocessed, unresampled audio at Android, expecting it to be resampled by Android's default crappy resampling, and have it be passed through directly to the DAC intact instead thanks to HiBy's engineering. Unfortunately, this is often not the default behaviour of apps, exactly because of the reputed crappiness of Android resampling of old. (it is actually very good on most phones these days, too, although fixed to one sample rate.)