WAN Failover with connectivity check

NSG devices have an option where WAN Failover is checking WAN up status.
USG FLEX devices don't have this option i the NCC.
If you have ISP on WAN1 and a mobile on WAN2, it will only jump to WAN2 if WAN1 is disconnected. But ISPs love to have their own devices as media conveters and more, then we have possibility that conenction will often be active, with the internet not working. Here the other solution from NSG with checking would be much appreciated.