That robot looks very nice indeed! I looked at the rooting instructions, and there's this lovely, bolded, line:
> This was patched in many new firmwares. Do NOT update your robot via the Mi Home app if you want to root.
Which sounds ominous if you're buying the robot new today. How do you feel about posting back here, or emailing me, or whatever, after you give it a shot? That bot plus open source firmware looks absolutely ideal.