In general, third-party routers can be used on a Swisscom connection, but they must have the ability to set the dhcp-client option 60. With the edge router, this can be done via the console using ssh. Operate it this way on fibre. On a DSL connection, however, you also need a router with a DSL modem, otherwise it won't work. The only one I know of is the Fritzbox and as far as I know it is not configured for a business connection. For DSL, I would advise you to use the centro Business with PPPoE passthrough. Then you can add whatever you want to it UDM/edge/pfsense etc...

In my case, the modem is in bridged mode. This means that it is no longer a router, but provides an Ethernet connection directly to the Internet. The edge router is then connected there. So it doesn't matter whether it's fibre or copper. It works perfectly. Many modems can be set to this mode, but not all of them work.
Hope this helps.

In principle, each port of the Edge can be configured separately, that's no problem at all. What you definitely need, however, is a modem that is located in front of the router. (PPoE)

The Swisscom network supports the following DSL technologies, depending on the network expansion situation:

- G.fast according to ITU standard G.9700, G.9701 and G.997.2
- VDSL2 Vectoring according to ITU standard G.993.5 and G.997.1
- ADSL2+ according to ITU standard G.992.5

I have no idea which DSL technology is in operation here. Does anyone know where to look this up?