Many lenders have brutal release fees to break up a blanket loan these days; many are 125% of the allocated principal balance.  

Even if rates went way up, I am confident you would still be ahead dodging all those fees and just paying down the principal after the PP falls off.Bottom line is this refinancing is too slim to be worth it right now.

Although rarely is it useful or beneficial to utilize (finance) that much additional principal and/or interest. 

If Interest Only ARM, then your cash flows would be higher but your principal would remain the same and may be less desirable given that you would be looking to pay if off in full between 7 and 15 years.Cheers!

The programs also attach all sorts of fees in order to finance the loan.  -- This is one fee among many which I found in the Hero program loan documents which could add quite a bit to your principal -- Program Administration Fee.

I also believe every dollar from my residents' paid rent goes toward principal reduction. 

Also consider, you've gone past the first 5 years of the loan which are interest/principal reduction ratio wise the worst years. 

Find key principals/sponsors. 

You'll have to pay beyond interest due to reduce the principal.  

And now I still get the benefit of some rental income and more importantly, principal paydown, appreciation, etc.