T-Mobile and Pinephone Pro in the US

[mikehenson]

Unfortunately, outgoing voice quality is awful. On a call between the Pinephone Pro with T-Mobile and an iPhone with Metro (which is owned by T-Mobile), the iPhone can be heard fine on the Pinephone Pro, but listening on the iPhone the Pinephone Pro sounds like it's at a harsh noise concert. Yes, this is with muting one microphone or going to separate locations to make sure there is no feedback loop. I'm worried there could be a hardware problem with the Pinephone Pro's microphone, and if so I don't know if the Factory Test Build for Hardware Checking would detect it since the mic technically "works", but I'm going to try running the FTB. Also, the phone died when it said the battery was 33% full.

The latest update just "broke" my phone again. The other person complaining about an echo.

1) Has anyone else used a Pinephone Pro with T-Mobile in the US, and can you comment on your experience?

I am your guy.

Device: PinePhone 32Gig (Used for building packages)
Device: PinePhonePro (Daily driver)
OS: DanctNIX Arch with Phosh
Carrier: USA - Patriot Mobile (T-Mobile SIM)

See this post for a complete install and setup.
https://forum.pine64.org/showthread.php?tid=18192

See this post for my experience on functionally 
https://forum.pine64.org/showthread.php?...#pid118783

2) Might upgrading to biktorgj's custom modem firmware alleviate any of the issues I've experienced?

YES! see my YouTube channel. Make sure you get the correct ADSP for T-Mobile