Is it possible to change the Netmaker server FQDN without much trouble? Or would it be nessary do a complete reinstall / rebuild of the network then

you could by changing the FQDN in docker-comose and restarting but all of your existing node would still try and reach the old server name. You would have do a leave and join on all of the nodes

Hmm yeah I tought so. Well I guess then I am going to stick with this domain 😄