Essential Phone has official Android Oreo beta, unofficial LineageOS beta
If you decide that you want to opt out of the software, there are factory images for users on Sprint and Telus and for unlocked phone owners. Keep in mind that while your existing data should be retained going into the beta, that cannot be guaranteed if you’re flashing the factory builds back on — either way, you should back your data up.
In any case, if you want to try something off the beaten path, you might want to get onto the successor of CyanogenMod, LineageOS. An unofficial version 14.1 ROM and kernel have been made available by an XDA-Developers member. While the image still needs baking, all the radios should be working and the stock camera application works, too. The instructions and files are available at our Via link.