"A sent HTTP request is evidence of an attempt" is the sentence I would put at the top of every automation brief. Most small business integrations are sold as "connect the form to the CRM", and the failure you describe, where the response is lost and the worker knows less than the CRM does, is exactly the case nobody quoted for.

Separating the submission identity from the customer identity is also the right call. Two deliveries of FORM-214 are one enquiry, while two forms from the same person can be two real enquiries, and most duplicate handling gets that backwards.

At Ascendra Ventures we write the finish line for these jobs the way you list it: the receiving record exists with the right fields, an owner is assigned, and an uncertain outcome lands somewhere an operator can see. Once that is written, the price and the tests both follow from it.

For the destinations with no idempotency support, which reconciliation approach worked best in your study, looking up an existing record by source id, or holding uncertain cases for a person to confirm?