A follow-up question: " send form data to a webhook and have it loop back and create/update a CO " is only for MKTO CO, or it's it also possible for SFDC CO?
It is possible, as long as the person exists in SFDC first. You don't want the webhook to create an SFDC contact (which it would need to in order to attach the CO) and then have Marketo create a dupe at the same time. So it would take some timing, like triggering the webhook upon the SFDC sync if the person doesn't yet have an SFDC record type, but yes, it could be done.
... View more