I have also sent personal hand written letters to people who are listed on the tax records of properties that are vacant.

You have experience with good performance results (I am assuming) so that could help drive approval on a DSCR loan.Also, you could just keep saving and waiting for the interest rates to head back down.

Be aware that not all of the companies have the qualifications to perform these studies.

No matter how great a 1-person manager is, even with staff, you’re one personal issue away from major problems.

I am a broker but would prefer to pay a person rather than a corporation on my personal investing. 

Perform the same task in each app to ensure a fair comparison.Load a property with pictures and details.Market that property.See what your marketing looks like from the public's perspective.Submit a fake application to see how easy the process is.Run a credit/screening report on yourself.Enter a maintenance request, assign a vendor, and attach a fake invoice.Enter charges to the tenant's ledger.Enter recurring charges and automatic late fees.Sign documents electronically.Run owner reports.After testing a few apps, one should clearly stand out.

Personal Cash from previous flips How did you add value to the deal?

These assets perform the exact same way in every market in the US. 

I personally would spend that much to fail a couple of times to learn.

It depends on the projected performance of your investment, on your financing, and on your overall financial and tax situation.