Just to be sure, how exactly is the HTTP request that you do to perform the zoom control?
We already had the idea of allowing users to setup HTTP requests directly from cockpit, but didn’t implement it because we didn’t have a clear use-case. If you can detail yours (e.g.: it’s a simple GET request to a specific URL, or it’s a POST request with some JSON body, etc), I can work on that. It would remove the need for a man-in-the-middle (node red in that case).