I don’t know if a phone that uses the open source version as base. Usually they build off open source or google and add in all the manufacturer/carrier bloat. For me to get off One Plus’s built in OS I had to go through this whole process on their website to get the code to unlock the boot loader.
I have lineage os as a replacement and it’s really cool. My mobile internet stopped working on it though :( my next phone is gonna roll with Graphene