Can the /remote/batch endpoint be used via WebSocket remote control in Unreal 5.7.4?

Is it possible to use the /remote/batch endpoint via WebSocket remote control in Unreal 5.7.4? It doesn’t seem to work. Other endpoints like /remote/preset or /remote/info work via WebSocket as expected.

Calling /remote/batch via an HTTP request with exactly the same Requests payload works.

I set a Passphrase header on the WebSocket connection and on HTTP requests (Unreal 5.7.4 crashes without it). Both HTTP and WebSocket use PUT to make the request. I tried using POST to see what it would do and I get a 404 back in both HTTP and WebSocket.

Does the Passphrase header also need to be set in the WebSocket message and if so how do I set that?

Where can I see logging of any errors or failed requests to the remote control WebSocket interface?