There is a misconception for the SMS API usage in MFA whereby we have created a whole set of extra steps to select a specific gateway.

These are entirely unnecessary and break the design of the API. The only time we should ever need to specify a specific gateway is for a testing page to allow you to test sending messages using a specific gateway.

The API itself is designed to select the most appropriate gateway for each individual message. Not all gateways are capable of handling all destinations equally. For example a national carrier may be available for local use for free, but only to local destinations. In this case the relevant plugin would only allow itself to be used for the relevant destinations.

We must remove all explicit selection of the gateway ID in the UI. We can also remove the hook which prevents removal of a gateway based on this usage.

Note: The documentation intentionally does not mention gatewayid usage because it is an internal feature of the API.