[c-nsp] PBR advice

[Hefin James [ahj]]

We are just about to get an additional routed internet link that we intend to setup as active/active with failover with our current link, and split the traffic using PBR. 
We will be terminating the links internally (after firewalling, etc) in a VSS chassis which will see 2 default routes of equal cost.

I've setup a lab that I can test PBR that uses the 'set ip default next-hop' settings so that local routing continues to work as currently set. 

However, the problem arises when if we get a failure which isn't local (Say 2 routers away).
I can track the availability of 2 IP address that's deep inside our providers network, but I can only apply tracking to 'set ip next-hop' and not 'set ip default next-hop verify-availability' 

Is there any other way of doing this or am I stuck with using 'set ip next-hop verify-availability' and have an ACL that excludes all locally routed traffic?

Thanks,
Hefin