If you already have an ample reserve fund in place for the unexpected emergencies, then using all your excess cash flow to pay down the loan principle should be OK.  

That does seem excessive. 

My MSA has a population in excess of one million and there are no NARPM credentialed individuals within 50 miles.  

Also if subsidy exceeds all closing costs and prepaid excess goes first to buying down the interest rate, and if more is left after that after max buy down it goes to the lender ad profit.

Capital contributions from your lending activity in excess of acquisition costs (if any) become working capital.

A slip and fall of child or hi earning person where the insurance does not over the cost of the injury or possibly a death, they could come after you personally. a car or plane crashing into the property that would be in excess of the insurance that you purchase.

The opportunity cost for stuffing cash in that property are in excess of 20% annually if you invest your cash in decent projects.  

. , not all plans allow excess after-tax contributions.

Aside from that I have an excessive use clause in the lease that allows that I can charge for excessive use. 

He talked about parking his excess cash with a crowdfunding site like Peerstreet where he is in a 1st lien position.