Right now, using the JS options, we can write to custom fields on the event object (or activity object really). It would be nice if there was a way to do this with router links as well because some customers would like to write to UTM's on the event object and it's complex to make that happen.

another option would be to update fields directly on the event node in the concierge router and to have the option to either update fields with values from the form or update static fields. It's common to have to set the "type" or something else like that. It would be huge to do that natively in Chili Piper