Unfortunately, it is not unifying compatible. I doubt you can buy a second USB receiver. I am constantly transferring mine from laptop to PC and back again.
Unfortunately, we have not had any experience with this combination so far. Therefore, the question was forwarded to our community so that someone who has already tried this can answer it.
With the dongle supplied, you have plug'n'play. If you want to use another dongle, you have to connect it first. I have never done this before, so I have no experience.
I hope a specialist answers you :( I bought the set 2x in the hope that the small USB stick can read both and I don't have to switch between home office and office.... unfortunately I always have to switch : (
A CH layout is QWERTY with umlauts and accents as you are used to. Do not be deceived by the product images. These are often only produced by the manufacturer as a US layout. However, the specifications are authoritative.
A general tip. Only American layouts have small enter keys. If you stick to Swiss layouts, you will certainly have a large one. LG (this one has a big one)
This keyboard is a Swiss Romand model with QWERTZ layout. It is specifically indicated as a Swiss QWERTZ keyboard in several official sources and retailers.