IPSec: VTI dynamic WAN IP [new config]

[GaardenZwerch]

Hi,
I have just tried if I could recreate route based IPSec tunnels with the new configuration interface.
Everything seems to work, but fot the VTI, I have to enter an IP address in the 'Local address' field. How should I handle this when my local IP is dynamic?
In the 'General Settings' of the connection it is possible to leave this field empty.
Thanks and best regards,
Frank