Select which upstream interface is being used for ACC connection

Hello Folks,

is there a way to define the upstream interface that will be used by an ASG to connect to an ACC?
Some of our Clients have multiple upstream interfaces. I would like to use Device access control which means I need to know from which IP the connection will come from. This is especially problematic if the ASG chooses an upstream interface with a dynamic IP.
It looks like the Upstream interface with the highest priority in Uplink balancing will be used however I'm not sure.
I think it might be possible to use a multipath rule for this but I didn't get it working so far.

Cheers,

DiePlage