The math behind Real Estate is not that complicated, Revenue - expenses and debt service = cash flow. 

That applies to replacement cost only and only if more $ is needed to restore the home to a pre-loss condition than what is available under coverage A.

Mgt, Landscape/Snow, tax, insurance, utility then debt service. 

Alternative Lenders – Look for private lenders or debt funds that focus on asset-based lending rather than borrower experience.

And you do not technically have to replace debt. 

best wishes  i dont do gap funding at all.. so no.. not something I would do we do JV deals every week but we have zero debt all cash and we control the process. 

If they notice you have another house and your debt to income can't cover it.

•Beyond that, flood insurance adds to a buyer’s monthly expenses, which can affect their debt-to-income (DTI) ratio and reduce their overall purchasing power.

DSCR loans go up to 80% of the purchase price and depending on the Debt Service Coverage Ratio and your credit score you can expect rates on a 30 yr loan ranging from High 6%- Mid 8%. 

If there is no debt service probably 30% is still going of the rent is still going to operating expenses which means that you only made about 480k or so. 480k rents + 800k property is the same 1.3million roughly.