Question in Changing the Transfer Rules in STAT 5.8.0

When changing the transfer rules for one step, I have a "Class: Apps Managers." How do I change the approver to this "Class: Apps Managers" to a different user who is in the "Apps Managers" queue?

Basically, what determines the user who is the approver for the "Class: Apps Managers?" Is it the owner of the "Apps Managers" queue for the specific domain?

And, after I change the approver, will it take effect on existing STAT CSRs, or new STAT CSRs only?

Thanks!