With the current SW 7.13 you can combine. However, each connection selects either DSL or LTE. There are (web) applications with multiple connections or connections that are established/disestablished in quick succession. These applications then see the LTE IP and the DSL IP - usually a different one. The result is that, for example, logins are lost and you have to log in "a thousand times". For example, my health insurance portal or the digitec.ch order page is not usable this way. So either DSL or LTE with the other as a fallback (backup) works perfectly.

The part has two antenna connections (you can see this in the technical data).