@stevetheobscure Tips:
Follow this and be patient, very patient...
First off, run it through the installer and install Xenial or Focal. If it boots into the OS, great, don't power off and leave it charged.
If it hangs though, at the Lenovo splash screen, this is the patient part....Follow these steps....
Power off.
Boot to recovery
In recovery Format data and cache, Mount the system and reboot to recovery.
In recovery now mount the system and reboot to recovery - do this at least eight times on the final time reboot to the bootloader.
Connect to the PC and with command prompt open run fastboot continue, leave it for 20 seconds, if no boot, power off and boot to fastboot and repeat this step four times.
Still no boot after step 5, boot to fastboot and run the command fastboot reboot. Do this at least four times, but by now, it should boot.
if the above steps fail, leave it for an hour and repeat.
It took a while for me to work this out, but it has worked every time on these tablets, I was just very patient.