Which constraint do you let bind when sizing mezz into a 2026 refi gap?

Sizing exercise I keep landing on from four directions and getting four answers.

Suburban office-to-flex conversion, stabilized, in-place NOI $2.35m. Maturing loan at $24m written when the coupon was under 4%. New senior quotes come back at $17.8m, so the sponsor needs about $6.2m plus costs and wants to fill most of it with mezz rather than write equity.

Run it four ways and you get four different mezz numbers.

Debt yield on the total stack. Senior alone is a 13.2% debt yield. Cap total stack debt yield at 10% and the whole stack is $23.5m, which supports $5.7m of mezz. That's the most generous answer and it ignores whether current cash flow can pay the coupon.

Combined DSCR at a stressed refi constant. Price the senior at today's coupon and the mezz at 12% current pay plus accrual, hold combined DSCR at 1.10x on in-place NOI, and the mezz shrinks to somewhere near $3.4m. That's the answer that keeps the borrower current through a soft year, and it leaves the sponsor writing a real equity check.

Stressed exit LTV. Take in-place NOI at a 7.75% exit cap instead of the appraised value, get about $30.3m, cap total stack at 75% of that, and mezz comes in near $4.9m.

Blended cost against unlevered yield. If in-place yield on cost is 8.6% and the blended stack cost crosses that, the sponsor is borrowing at a rate the asset doesn't earn, which caps mezz well under $4m regardless of what the other three tests allow.

Every one of these is defensible and they're $2m apart. I have a view on which one I'd hold to in credit, and I'd rather hear the room's before I say it.