I didn't watch it, but I didn't pay attention either.
Have you made sure that the "optimised charging" setting under "Battery status & charging process" is not responsible for this?
We have three of these things in use, next to the bed, when travelling, etc.
So far they've always been problem-free - although they do get quite warm and I could imagine that this could sometimes be a problem.
But there are few devices like this - either they have a wall plug, which becomes difficult when you're on holiday, or they have more power and are three-pin (and there are countries where three-pin sockets are in really short supply).
Yes, you can connect the Nexode Desktop (100 W) to a power strip or extension cable. It is a standard 100 W power supply with a Euro plug, which is designed for normal household use as long as the power strip can handle at least 100 W.