I use this mesh access point with the Zyxel router from Yallo. Since Yallo belongs to Sunrise, I assume it is the same.
Works fine; download the MPro Mesh app to your phone for installation. It's very easy to install, no technical knowledge needed.

I use two Zyxel WX3100 with a Zyxel NR5101 router. Everything works fine, the configuration is simple to do with the MPro Mesh application from a smatphone.

Yes