This is by way of a comment, not a question or issue.
A few weeks ago my 2021 model Nano 7 stopped doing its thing owing to no fan function. My workload on the unit is quite low. Communicating with Wayne, we diagnosed a motor or controller failure. Given I was disinclined to send my Nano away, and have experience with small electronic devices, I volunteered to risk installing the newer model motor, controller, and vibration absorbers myself. A week later the parts arrived and, with some further conversation with Wayne about details, I successfully did the replacement.
For some reason, fan calibration (looking for 'transitional fluidisation' matching the video) reminded me of visiting Rotorua; a bit more active.
Part replacement on the Nano is not difficult if you have been there before with similar work (de-soldering and soldering may be involved), remembering that if you stuff it up then that is not Kaffelogic's fault so don't volunteer in haste or maybe not at all.
Most importantly though, I want to note here with thanks the prompt and helpful service from Kaffelogic through Wayne.
I have not yet started full roasting again as we have roasted beans kindly supplied by friends as care packages to get through first.