Debt yield is calculated both ways, depending on the reason for calculating it. When sizing a new loan, debt yield is calculated on the initial loan amount (i.e. Static Debt Yield). When used as a covenant to an existing loan, it is calculated on the outstanding loan balance at the time of calculation (i.e. Dynamic Debt Yield).
This was also brought up in the Accelerator forum, so if you’re an Accelerator member check it out: