Question about XGO3 Kids - 708563

Correct, Multi Device does not work to make calls, there is an error message for the caller.
Swisscom has a special plan for kids' watches (cheap, simple, good).
www.swisscom.ch/de/privatkunden/mobile-handy-abo/jugendabo-k...
I ordered the physical SIM variant, I don't know if it works with an E-SIM.

We have the watch in operation with a physical SIM. I don't know if and how you could set up an eSIM.
We don't use a swisscom SIM. Should work, of course.
But not a multi-device, as you can make calls to the watch. Outgoing calls are also made. As far as I know, multi-devices have the same phone number.
I assume there is an eSIM version.
Videos cannot be made with the watch.
Outgoing text messages only predefined text lines.
But the function to send voice memos is practical. With longclick, the administrators are called.

I can't imagine that with the multi-device. The watch only works in conjunction with an app and 10 contacts stored in it. Access to a mobile or its data is not possible.
You need a physical SIM card.