Looks like the email works, because they got back to me (not with an .img file tho) but with the same instructions for upgrading to Android 8, and the android tool.
"Here is the rooting FW instruction and tool (Mars) for your reference:
Instruction:
https://mega.nz/#!eNYxxARb!-2FQ3jB7O...PP75J_OwK6B7cQ
Tool:
https://mega.nz/#!OZJBRQ5b!zTTN1rqgC...YVbDjxAoUbwMN4
Please power off the device or press power button for 10 seconds if device cannot be power off, then start the rooting schedule as the instruction."
For anyone's future reference. Guess I'll try it again, tho I've alr upgraded my Mars last year.