Can a gateway group be used for outgoing interface for Unbound?

[Panja]

Like the title suggests:
Can a gateway group be used for outgoing interface for Unbound?

I have 3 OpenVPN clients running and created a gateway group, as failover.
So when VPN 1 goes does, it switches to VPN 2, etc.

In Unbound I would like to be able to choose the VPN Gateway Group as outgoing "interface".
So when VPN 1 is up, it will do the request through VPN 1, but when VPN 1 is down and it switched to VPN 2 it will do the DNS request through VPN 2.

Is that even possible?
I know I can select multiple interfaces in Unbound but it will use them all and not only one (which is currently active).