The possibility to create a webhook through the FME Server interface is great, but when choosing the parameters I miss the Advanced parameters which you had in the Run Workspace form:
You can always add the Job Directives tm_ttc, tm_ttl and so on (https://docs.safe.com/fme/html/FME_Server_Documentation/ReferenceManual/Job_Directives.htm) to the webhook manually, but it's not so obvious and I don't think every user knows this directives