Depending on which brokerage you use, you could possibly borrower against your securities holdings with a line of credit (similar to a margin loan) if it's not a retirement account. 30-35% of the balance would likely be within reach, but make sure you FULLY understand margin calls and when they would trigger.

If you like the margins, go for it. 1 thing though, double no triple check your rehab & ARV numbers.

They have deals you can look at with better margins and less competition compared to on market. 

This would be my single biggest piece of advice, as a rough location with little upside offers little margin for error.I sent you a DM to help out :)

It may weed some out who were marginal financially.

Creative financing is really how I am able to find cash flowing STRs for my buyers right now.. the margin is really low with DSCRs right now especially with taxes and insurance in FL.

The refinanced loan amount will be smaller and the rate will be less so the payment will be quite a bit less and suddenly a marginal cash-flow is decent cash-flow.  

Did you buy "points" to reduce the rate margin?

The big question is this - is this 'marginal' area going to a) stay where it is? 

But I think once you are buying 3rd you should be lower leverage or have done value adds to boost the rents so have safer margin/ratio.