“When a webhook is received” workflow trigger limitations

I use the “When a webhook is received” trigger in workflows, and it’s been a hassle not being able to add to or fully edit events after creation. I can’t find documentation on whether it’s possible to:

-Add fields to an event after it’s been created without generating a new webhook URL
-Change the match property after creating the event
-Authenticate incoming requests

Are these current limitations, or am I missing something in the setup? Here’s the documentation I’ve been referring to: Set ‘When a webhook is received’ workflow triggers

Thanks in advance for any guidance!