Your ratio is the reason the fifth deal died, not the deal.
Conventional investment lending counts every mortgage you hold at full weight and gives partial, delayed credit for the rent that pays them. It degrades with every acquisition even when every property cash flows. That is a consumer formula pointed at a business.
DSCR replaces you with the property.
Gross rental income divided by PITIA, qualified at the original note rate. No personal income, no tax returns, no debt-to-income test, and borrowers who do not provide employment verification are still eligible.
One line makes portfolios possible.
Additional financed properties require no reserves on this program. On most investment lending each property you own adds months of reserves to the next file, which is exactly what stalls investors at three or four properties.