Changing talk2m registration remotely

I have a Flexy 205 with fw 14.1 up and online and functioning and accessible through ecatcher.

Can I switch to use the wifi extension card as the WAN interface while still remotely, without taking it permanently offline and not be able to get in to it?

I would not recommend doing this without a backup plan (an alternative way to access the remote network, for example, being able to connect to a remote laptop with Teamviewer.) If something were to go wrong, you could lose access to the Flexy.