Xiaomi Mi 8 Light

or please tell me if I can do that in some other way

Hi @rebelmuffin on the question as to how you can build the ROM yourself please refer these two posts

Docker : https://gitlab.e.foundation/e/wiki/en/wikis/build
Non Docker : [HOWTO] Build /e/ without docker

This only works for devices supported by LineageOS.

https://github.com/search?o=desc&q=platina&s=updated&type=Repositories