Dual WAN SD-WAN configuration with service exposure on both links

Hi,

I have a customer who currently uses two WAN connections: a primary one (Swisscom) and a secondary one (Horizon).
Some services are also exposed only on the primary WAN.
They asked if it’s possible to combine the two connections so that, in case the primary wan becomes saturated, part of the new traffic is automatically redirected to the secondary wan.
Additionally, they would like to expose services simultaneously on both WANs.

From what I understand, the only way to address the first issue is to configure an SD-WAN, adding both WANs to the Virtual Link Zone, including this zone in all policies and static routes, and then creating an SLA monitor.

As for the second point, how could that be handled?
Would it be feasible to create a virtual VIP address?

Thanks,
Cheers