I figured out a simple way to capture the details of additional delegates. Simply have an "Additional Delegates" web form as the Thank You Page of a sales form that captures the payment. The Thank You page of this URL is itself. If I put a Big Box "No more Delegates to Enter" an link to a finished thank you page then I get the info I want.

Can I make the Company mandatory on the order form and bring that data into the resulting web forms?

I can have actions on the forms that tag and add to a fulfilment list.

I could also have an email template of the certificate as part of a sequence after the event. Obviously I would need to manually intervene if they did not attend.

The only thing this does not do is valid the number paid for is the same as the number entered. Any suggestions?