What does affect your file is any change to your own payment amount, whether from a renewed repayment plan, a consolidation or an income-driven adjustment through the Canadian system. That new payment simply feeds into a 39 percent gross debt service ratio and a 44 percent total debt service ratio like any other debt.
If your payment has changed recently, ask your lender to use the current, documented figure rather than an outdated one, since the difference can move how much mortgage you qualify for either way.
A mortgage broker can confirm exactly how your specific loan is being treated before you shop for a home. Get your hand-reviewed valuation from Joel Dyck.