CoPilot Reply-To field types

We have customers that are looking to create CoPilot outreaches that populate the "Reply-To" field with a formula field. Right now though, our only supported fields are Email and User Lookup fields. 

It would be nice, if possible, to allow other fields to be brought into the Outreach like formula fields containing the correct information (email address). This would allow other information to be used in the outreach.

Thanks for the help!