Qualcomm VoLTE audio codec preference

[NathanA]

Does anybody have knowledge of, or access to materials that explain, how to configure audio codec preference order on older Qualcomm modems (specifically for VoLTE)?

I have MSM8994-based UE, and /efsprofiles/overideconfig is not used by this modem firmware. Neither is NV 73690 (qipcall_audio_codec_list).

I wonder if NV 65958 (voip_prfrd_codec) would be appropriate location for this config, but I cannot find any documentation on it.

I want to order AMR-WB above AMR. Right now, for outgoing call, UE currently advertises both AMR and AMR-WB in the SDP of SIP INVITE, but AMR is higher priority, so it gets picked. Also for incoming call, even when AMR-WB is included in SDP media types from network INVITE, UE picks AMR instead.

Thanks for any help!