Can I refi a bond for deed?

[Rachel Gniady Hurst]

So I made an offer on a property that will ultimately be a STR and the sellers countered with a higher ask but bond for deed amortized over 30 w/a 5 year balloon. I'd be getting a better interest rate than market and the purchase price difference is negligible so I would actually cash flow more in the bond for deed scenario. Here's where I'm stuck. The sellers want 20% down, which I have but I'm worried about the refi on the back end when the balloon comes due. Can I refi a bond for deed or will I have to start over and put another large down payment down? I've bought 3 other STR's, all with DSCR loans so that's how I'd look to refi but not even sure that's possible out of a bond for deed. Hopefully someone has run across this before.

TIA