[SignalR] Possibility to cancel long running hub method from client

I´m not quit sure if this post is more of a question or a feature request.

I noticed that the InvokeAsync<TResult>(HubConnection, String, CancellationToken) method accepts a CancellationToken. As far as I understood this token only cancels the invocation (and waiting for a result, …) on the client, while on the server side the method proceeds. Is this correct?

If so wouldn´t it be a nice feature to allow such a cancellation? I saw that Google offers this possibility in their gRPC framework aswell:

Cancelling RPCs Either the client or the server can cancel an RPC at any time. A cancellation terminates the RPC immediately so that no further work is done. It is not an “undo”: changes made before the cancellation will not be rolled back.

When my understanding is wrong please provide me an example on how to do a cancellation of long running hub methods from the client.