Two endpoints on Digium PRI gateway to two different VSPs

I assume the Digium PRI gateway product line (like G400) is running Asterisk.
In my scenario the device would be behind a NAT router/firewall with dual WAN.
I would like to configure two SIP endpoints on the PRI gateway registering to two different VSPs, but each going out a different WAN interface. I would have static routes on the router for that purpose.

I know that such a thing is not possible with chansip, as it only knows about one external IP address, which it would put in the SIP headers, which would be wrong for one of the trunks out to a VSP.

Or is that still possible (maybe because the G400 gateway is running PJSIP and not chansip)?

Your scenario is currently un-handled by Digium’s PRI gateways.