After doing some calculations, I realize it behooves me to pay at an accelerated amount of the mortgage up front.

Obviously, as mortgages go, the lender has you paying mostly interest up front and principle years down the road. With a loan for ~$39,000 we are paying ~$170 more than what the bank is asking, to accelerate the loan pay down and minimize the interest needed to be paid. The rental's cashflow allows for this and as I am still happily working my dayjob, I can afford to 'play the long game' and defer cashflow into my personal bank account until years down the road.

My question for all you wise and experienced investors (and vendors) out there:

Would it be profitable to refinance under new 15 year mortgage? Given the already accelerated payments, and the current interest rate of 5.25%, I am wondering if I should just refinance and make the same monthly payment but with less of that payment being interest. Would a bank want to take their time to do this with such a low loan amount?

Thanks :)