Website ruleset not implemented and actioned when using API label request.

After a lot of testing, it seems that labels requested via API are not subject to shipping rules, can you please confirm this is correct?

We use the Easyship API to request a label with FedEX International Priority and wish to change the shipping method to FedEx International Connect Plus IF the shipping destination = such and such countries via a ruleset defined on the Easyship website.

However it seems that ALL shipping rules are completely IGNORED when using API requests.

Why is this and how can we apply rules in EasyShip when using API requests when we do not have access to change the API requests.

Label requests have been hardcoded to use the FedEx International Priority and we hope to create a rule that changes this to FedEx ICP based on country, using the rule 'If shipping service contains "FedEx" '

We even tried REMOVING the FedEx International Priority from the list of prefered couriers (with the check box selected to only use these couriers) so only FedEx FICP would be selected but the ruleset yet the FedEx label is still International Priority.

(The current ruleset on our account has been reverted after testing so please do not assume it is a rule set mistake with the current configuration)

How can we set rules for API created labels using the website?
Thank you if you can help.