Feature request: update statusCallback url for an in-progress call without url redirect

Disclaimer: I'm fairly sure this is an issue with Twilio's REST API, not the Python SDK since I can't find any point in the request chain where the statusCallback param is ignored when url is not set. Feel free to dismiss this issue if that's the case. I'm only submitting this issue here because I'm not seeing a request show up to the Twilio API in call logs when I have run the update command (when url is not set), meaning there's a small chance the Python SDK is not sending the request somehow

The Twilio docs claim a CallInstance cannot be updated with statusCallback without also updating the url parameter. Our codebase only has knowledge of the new statusCallback url after certain logic has been executed which generates the TWIML response. So we're forced to set a new API endpoint on our router that just retrieves the output that was generated in the previous API call. It seems trivial to me that the Twilio API could accept updating the statusCallback value on the call instance without needing to redirect the request to a new API endpoint

Start by reviewing the Twilio REST API documentation for CallInstance updates and the Python SDK's CallInstance.update behavior. Verify whether a request is sent when only statusCallback is supplied; done means confirming whether this requires an SDK change or is a Twilio API limitation.