The pin seems like a security feature. If the seller has not given the pin, the device might be stolen. Also the video author blames Jolla for telnet not bring available on MacOS. The linked video does not mention any of the other points.

Congratulations! Time to add a MMU to it ;)

If you like to tinker but don’t want (and don’t have the time) to build something like the ERCF or Tradrack, I would suggest looking at the 3MS. It is a DIY solution consisting of a stepper and extruder per filament (you can re-use an old mk8 extruder if you have one) and a splitter.