RFC: shared webhooks
Nice to see some movement on this front, I just read it and although I am not familiar enough with the way prototypes works it seems overly complicated. This may not be the type of feedback you wanted but since prototypes are in development since I started using concourse (~ 1.5 years ago) I imagine that following through with this proposal means that the current webhook system is going to be there for quite a while.
I really love concourse and this is by far the best automation system I have used so far but it each features takes years to develop it might become the ultimate automation tool at some point but in the meantime the temporary fixes become permanent and it just generate confusion for newcomers.
I am currently using concourse-webhook-broadcaster because there is not real way to use webhooks otherwise with dynamically generated pipelines (for pull-request, release, deployment).