The context is a staff member taking a phone call from a member and then filling in a webform including a payment for them.
The webform is added to the actions menu so the webform is passed '?cid=XXX' to load the contact. The problem is that when it comes to payment (by Stripe), the billing block is loading the details of the person filling in the form, not those of the person on the phone.
How can webform be configured to use the details of the contact on the form? Answers involving code writing are fine:-)