Automate changing of shiping service when updated through xml feed

[SA]

On custom stores, on orders awaiting shipment.

When a custom xml feed is pulled it maps the requested shipping method to the method set up in shipstation - Great.

If the order is updated in the xml feed whereby the requested method is changed shipstation recognises the requested method but doesnt update it through the automated mapping.

It could do with a, if (requested xml method != current method){re-run service mapping}.  Probably with the ability to turn this off/on as I can see the flaws for some users who would import a generic method then set the service through shipstation which this would otherwise override.