You can use this flake to add cosmic to your configuration

Thats interesting, I am using lineage as well (oneplus 6t) and do have the app com.android.devicelockcontroller. This could be some junk added when I enable the gapps magisk module which I generaly keep dissabled though.

Excuse me, but real programmers use butterflies.

Take a look at rooting it, maybe you can find some way to use it to stop it from just being e-waste. https://npjohnson.github.io/Spotify-Car-Thing-Root/

Rooting is a slightly separate thing from sideloading a custom rom, rooting gives apps you give permission to access to system files whereas sideloading a rom replaces the system files but doesn’t necessarily give you root access. Both involve a similar process of unlocking the bootloader, installing a custom recovery and flashing a file so it is easy to get the two things mixed up.