I made a build for the as-of-yet unsupported Poco X3 NFC (Codename surya). I do already use it, but please keep in mind this is work in progress.
Here is what I used:
Unlock Tool: https://www.xiaomitool.com/V2/ (highly recommended!)
TWRP build by mahajant99: https://forum.xda-developers.com/t/recovery-3-5-0-0-unofficial-twrp-xiaomi-poco-x3-surya-karna.4168511/
Device/Kernel Sources for Q-Build: https://github.com/gardiol (this will be the LOS 17.1 maintainer later on it seems)
- for me bluetooth audio is broken
General discussion about LOS17.1 for surya at XDA: https://forum.xda-developers.com/t/rom-10-lineageos-17-1-unofficial-surya-karna.4202533/