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

The number of DSCR (Debt Service Coverage Ratio) loans a lender will offer can vary depending on the lender, your financial situation, and the property cash flow.

I know there are services that provide proof of funds but I view that as misrepresentation. 

I.e. say your plumber has a fixed $150 service call fee.  

Analyze properties by looking at gross rental income, operating expenses, and the debt service coverage ratio (DSCR above 1.25 for rentals).

If you are open to non-traditional methods of financing, you could use a debt service loan to bypass that requirement.

Whether you’re offering services, partnering on projects, or exploring your own investments, leverage your expertise to identify undervalued properties and add value.

What kind of seasoning is generally required as it relates to the rents/revenue as it relates to servicing the note, etc...I currently own one PadSplit (acquired via Subject-to) that has been up just over a month.

I like the tub (it wasn't cheap, about 12 grand) but there's not great service options where I live and not sure if I would get it again since I mostly have to take care of it. 

There's a value to that service.