All correct. I record it on my PC's creative x-fi. Just one detail: RMAA generates a standard test tone to be played on the device under test, and then compares the recorded playback with its master test file to build its statistics on sonic performance. It really is a 5-click process.
HiFi DAC is always-on, except to test its performance against Qualcom's standard DAC. By sonic performance I mean RMAA's figures on noise, dynamic range, crosstalk etc..
Concerning the frequency response I directly look at the curve. Strangely RMAA's recorded performance on that one is unreliable. I validated this also with pink noise playback at 44.1, 48 and 96 kHz. And frequency response-wise the result was the same as in RMAA's curve, except than strangely RMAA's can classify as good performance a freq resp curve rolled off at 15 kHz, which produces a nasty audible alteration in music playback.
To wrap-up, both for cases with Hi-Fi DAC on and off, ideally frequency response curve shall be flat. If it isn't, in my opinion there is a problem.
The description is code named as player used on android-test file encoding format for playback.
Anyway all this could possibly have been caused by resampling. So the fact that V30 seems to be free from these problem, might mean that resampling issue has been fixed.
But I leave this topic clarification to you lucky V30 owners .