The default policy on /Inbound/Default and /Outbound/Default has an inheritable policy of Priority 3. Any class without a policy will inherit this policy. In addition, this policy also controls all traffic that is not otherwise classified in the traffic tree. The Priority 3 policy works well in most deployments.
Therefore, we do not recommend modifying the default policy for /Inbound/Default and /Outbound/Default traffic classes as this change could impact a lot of traffic.