Allow custom fields to be skipped in Agent Transfer if the field is optional in Support

In Messaging, we'd really like to collect order numbers from customers who have that handy, but we don't want that data collection to be a roadblock between Requesters reaching our agents (or worse, for customers to enter random numbers in just to get past the form).

Currently, even if you have a custom field "Required to submit a request" unchecked in Support, on the Messaging "Transfer to Agent" step, that field is still treated as Required to proceed to the next step: 

Ideally, fields in Messaging should honor the required vs not required settings applied to that field in Support > Tickets > Fields and give customers an option to skip a custom field if it's optional.