I don't know the answer.   The documentation says the rules are executed in order.  I'm guessing [hoping] the rule processing stops on the first match. https://documentation.meraki.com/MX/Firewall_and_Traffic_Shaping/SD-WAN_and_Traffic_Shaping#Creating_Shaping_Rules   Also note the warning: "Note: Traffic shaping rules for applications are applied per-flow, so setting a limit of 5 Mbps to three different applications will allow 5 Mbps to each application."   If you assume this the answers to your questions pop out. ... View more

That is correct.  Once a flow starts using a specific WAN port it keeps using it until that flow expires.  This is not configurable or changeable.   Hopefully your primary circuit does not fail that often. ... View more