LineageOS offers an official International Samsung Galaxy S6 build, which does NOT install on the T-Mobile USA S6, but there's an unofficial T-Mobile USA build that does, but after installing it just hangs on boot. (To install I used TWRP and adb sideloaded LineageOS, Stock Open gapps, SuperSU in that order) Has anyone had success running LineageOS on the T-Mobile version of the S6?
I have no idea if it's safe, or a good ROM, The github is here but it's lacking information, an issues page, or a website on it, and it only seems to be referenced in broken english blogs, and scam searches appear when searching
nexus-roms.eu on duckduckgo, and their site is down. So I would not recommend it.
It does seem to install & boot on the T-Mobile USA Samsung Galaxy S6