Yes BB seems to be the closest option but in order to unlock it’s bootloader you also need to authorize on some manufacturer’s site which is (to my understanding) a concern in the “consumer’s right to repair” way - if I can’t upgrade a system after its support ends the phone becomes e-waste, and giving your phone number, name, email address to the Chinese government is at least questionable from privacy standpoint. I could be exaggerating though
File names and directories🗿