2) Maintenance Reserves: So many factors here to consider!

For any one person's situation, one approach may work better than another.For someone who has the cash flow, and has the equity but not the cash reserves, the HELoC can work, but is NOT the only choice.

We opened availability on Airbnb, and we've had a lot of short stays reservations. 

The property may not have any vacancies, but if it does, just make sure you have enough reserves to cover that. 

So you must cover that 10%, holding costs, and have reserves for overruns. 

Our other 3 buildings (two duplexes, one 3 unit) are basically stabilized at this point so just continue to maintain them and build the reserves even larger from the cash flow they spit off.

Expenses: What are the operating expenses, including taxes, insurance, maintenance, and reserves?

I'd consider doing some kind of cash out refi on the property at a number you're both comfortable pulling out, while still leaving $ for reserves to maintain the STR you currently have.

I've included an example below to help illustrate this.So different lenders have different rates (which do vary even for DSCR loans) but these are factors they all consider.See example below:DSCR < 1Principal + Interest = $1,700Taxes = $350, Insurance = $100, Association Dues = $50Total PITIA = $2200Rent = $2000DSCR = Rent/PITIA = 2000/2200 = 0.91Since the DSCR is 0.91, we know the expenses are greater than the income of the property.DSCR >1Principal + Interest = $1,500Taxes = $250, Insurance = $100, Association Dues = $25Total PITIA = $1875 Rent = $2300DSCR = Rent/PITIA = 2300/1875 = 1.23If a purchase, you also generally need reserves / savings to show you have 3-6 month payments of PITIA (principal / interest (mortgage payment), property taxes and insurance and HOA (if applicable).

ONLY when I pushed further, did they actually release those dates (and I received an email with the subject: Your reservation XXX was cancelled at property YYY), and those dates showed as truly open across both calendars.