I'd be heavily focused on mitigating that future tax liabilty rather than directly supplementing that income.

If It is a wholesale DSCR lender that also does TRID loans, they might require a bit more paperwork, such as a VOM, mortgage statements for properties currently owned, and credit supplements on mortgages on your credit report.

I also helped my mother get 2 rentals to help supplement her retirement, mistake #1b.

Our portfolio currently cash flows, but cash flow isn’t our top priority right now since we plan to use this portfolio to supplement our retirement in 12 years when I leave the Army.My biggest challenge is committing to an out-of-state market.

Unless there is a history of STRs in the property already and you have experience with STR, you really wouldn't be able to supplement your income with that. 

How they could be more intertwined and supplement each other. 

It's not quite as easy as renting out two sides of a duplex, but with the right marketing and management you could rent out the extra unit to supplement the mortgage payment. 

Ask the builder or their legal representative for a copy of the CC&Rs (Covenants, Conditions, and Restrictions) or any supplemental documents specific to the development.Financing Considerations: If you’re financing the property, some loan types have limitations on renting out a home within the first year.

Is the option government supplied insurance where taxes supplement the insurance?  

If you just want to make some quick cash so you can supplement your retirement, then sell it and relax.