Jay, I would only pay off that property if you wanted to use it as collateral for your future investment properties and have a lender that would allow you to use that in lieu of cash down payments. 

Essentially you establish an Offshore trust; then an offshore finance company makes a loan to you in an amount equal to 95% of the real estate equity you wish to protect; the loan proceeds are transferred by the lender directly into your offshore trust and invested in a certificate of deposit (CD) issued by the offshore bank; for collateral you give a mortgage on the properties protected.

We are seeking a lending partner that would be willing to provide long term financing collateralized by the STRs and also by the LLCs that own them, which have other assets.

Cross-Collaterize.  

The request is currently being reviewed.June 05, 2018The borrower has been non-responsive and a demand letter has been sent to start the foreclosure process.May 04, 2018The originator is contacting the borrower regarding the late payment.March 01, 2018The borrower has agreed to a 3-month extension.February 12, 2018The borrower has listed the collateral for sale.

Slack for messaging between team members, Sharefile to store collateral, company docs, marketing materials, etc.

I'm using equity in one of the free and clear properties as collateral for my "required 20% skin in the game".

If that's the case you may have to live with the status quo or contribute to the cost of running an independent line for the other property.Before you make that decision though, as I wrote above, I would confirm you have marketable title before putting any more money into the property unless you plan on you and your heirs owning it forever and never being able to get a mortgage with it as collateral. 

Blanket loan or cross collateralization are the terms you're looking for.

I recently did an addendum to my LLC where my partner can sign contracts as long as I am given 3 day notice on the terms of the contract they are entering BUT they can't enter a contract that binds my shares of the LLC (i.e. use the property equity as a downpayment, collateral, etc).