Are there any real world Dual Hub Dual DMVPN design guides that handle WAN links properly, NAT, and all other caveats?

Everything I see online simulates the WAN links as a switch. Or they just do a default route from the hub and don't take into account WAN traffic.

Here's a scenario I've been working with in GNS3: https://imgur.com/a/KBoZ9

I am looking to keep the dual hub dual cloud design and I want the two tunnel interfaces on the spokes to always be up. However when I have that, I cannot handle WAN failover properly. Specifically I want WAN1 on each spoke to be the default route out to the WAN. Then if that fails I want WAN2 to be the primary WAN connection and ALSO the DMVPN failover path.

So the requirements again:

Both WAN links in failover for actual WAN traffic

Both WAN links active as DMVPN cloud tunnel ints

Failover of WAN