I understand there’s a new action in works that’s called “Trigger webhook”.
As a placeholder, all you’d need to do is remove the check on the “Make” webhook URL in the Customizable form workflow. Allow any URL to be placed there. This shouldn’t even require to be placed on a roadmap
Trigger webhooks is in works, that’s all I know. And that it should fit your needs.
PS: It requires to be placed on a roadmap as a roadmap can also have the usefulness to inform customers that the most requested features are coming/are actually in the roadmap.