Can BIG-IP DNS recursion only my domain?

Is there a way to create iRule to check if DNS query is our handle zone or not?

If it our zone > use dns profile which allow recursion Process Recursion Desired is enabled (by default)

If it not our zone > use dns profile which allow recursion Process Recursion Desired is disabled 

But problem is many CNAME is resolve to cloud (for example www.ourzone.com IN CNAME abcw123s.cloudflare.com. )

When we query www.ourzone.com, F5 will use dns profile which recursion is enabled. But

When F5 try to recursion to see IP of that CNAME (abcw123s.cloudflare.com.) , What dns profile it will used?