Appreciate the correction.

They aren’t based on LOS. They should be based on AOSP.

There a bunch of custom roms for RN11. Crdroid and Pixel Experience have a good reputation.

https://crdroid.net/ https://get.pixelexperience.org/

You can unlock the bootloaders on Xiaomi phones. Just be aware that not all have custom ROM support. Mainly those using Qualcomm SOCs have some support.

Aren’t Huawei bootloaders locked?