Emailing of Invoices - Configuration setting

Emailing of Invoices - Configuration setting to use only the E-mail address sitting on the customer record

We are preparing to start E-mailing Invoices from Command. As I understand, the E-mail address sitting on the customer record carries into all projects created for that customer. When invoicing, if the ticket came from a project, Command will use the E-mail address from the project - and not the customer. Would be nice to have a configuration setting that we could set to force Command to ONLY use the E-mail address assigned to the customer record - and NOT USE what may be on the project.