Some notes on running a Samsung Galaxy S4 i9505 in Australia in 2018
My first high end phone, still perfectly capable of everything I need from a smart phone and now dirt cheap on ebay so I'm basically going to keep buying them till there's no more to be had (or someone releases a Spectre-immune CPU phone I guess now).
Baseband: XXUGNG8 I upgraded the baseband a bunch of times including to some alleged Telstra OTA packages, and found I lost wifi. The actual modem and APN-HLOS don't seem to matter much but...the XXUGNG8 bootloader and related files are vitally important to getting sound to work.
OS: Lineage OS Loved Cyanogenmod, like seeing it continued. There's a patch to the SELinux config needed on newer android to allow the proximity sensor to calibrate properly - the symptom is an apparent freeze when making/receiving calls and its to do with SELinux only allowing the phone to use the default prox-sensor thresholds - which if your phone meets them, great - if not - then it will appear broken.
I'm hoping to get this patched in the upstream soon.