Might be a stupid question, but does anybody know if it's possible to combine hot and active standby modes?

e.g.

I have a customer that has a standard leased line coming in and wants to use Hot-Standby on that circuit, however, they also want to bring in a second line to a separate building which is on the same LAN (VLAN'd) to allow internet redundancy. Is it possible to have a second pair of Hot-Standby Drayteks on the new circuit configure in Active-Standby to provide another route in/out?

Cheers