@Miustone
I see that you disabled compander & set analog volume to 20 & digital volume to 84 for DAC in mixer_paths_noextcodec_snd.xml, which is good.
My only advice is to switch DAC from LOHIFI to HIFI mode. Battery increase for slightly better audio quality is non-existent/negligible.
From:
<ctl name="RX_HPH_PWR_MODE" value="LOHIFI" />
<ctl name="RX HPH Mode" value="CLS_H_LOHIFI" />
To:
<ctl name="RX_HPH_PWR_MODE" value="HIFI" />
<ctl name="RX HPH Mode" value="CLS_H_HIFI" />
&
From:
<ctl name="RX_HPH_PWR_MODE" value="ULP" />
<ctl name="RX HPH Mode" value="CLS_H_ULP" />
To:
<ctl name="RX_HPH_PWR_MODE" value="HIFI" />
<ctl name="RX HPH Mode" value="CLS_H_HIFI" />
Here, you can see that DAC is either in UltraLowPower mode or LowHifi mode.
My device, Poco X3, shipped with ULP mode by default and while it's sound quality was ok, it's amp was so weak. Switching DAC from ULP to HiFi mode along with analog & digital volume increase increased maximum volume nicely & slightly improved sound quality.
I accidentally stumbled on this thread and I remember your work from ZTE Axon 7 days which you quickly abandoned. While I prefer more system-ly and native solutions without using scripts or Magisk, I think that you have an interesting work.
I am considering to join the Sony family once Sony Xperia IV launches. It looks like an very interesting device to me. And I want to experience great design & build quality with clean software for reasonable price after using this plastic mess lol. The only Xiaomi device where I liked design & build quality was white Poco F2 Pro.
Cheers!