Just a quick update Hal9k released a Rooted Android 9 and it was so easy!
It's not required but he's released his own "Mod Installer Pro" for just over £8 which allows you to install a custom recovery for either Android 6, 8 or 9.when the unit boots into the newly installed recovery you can then insert a Fat32 USB stick and install Hal9k's Rooted Android 9. If you don't want to buy the Mod Installer Pro you simply use the SD card slot and do it manually and for free (but of course you'll need to buy an SD card if you don't already have one)
Hal9k's official Mod Installer Pro Link
And this YouTube video has the Google Drive link to Hal9k's Rooted Android 9 OS. Remember, we have the PX5 CPU
https://youtu.be/VrRkga1hwLc