We've been using a rental manager for one property and we're about to purchase a second.

However, if you’re unsure about future property values due to the unique nature of the property, this could pose more risk.What You May Not Be Considering:Financing Flexibility: Using a HELOC for repairs is a solid plan, but make sure the loan terms are favorable and the rates are manageable over time, especially with interest rates fluctuating.Vacancy and Maintenance Costs: Once all units are rented, factor in potential vacancy periods and ongoing maintenance costs, especially with multiple units.In conclusion, while the repairs are a big expense, the strong rental income potential suggests it could be a good deal if you manage the rehab costs well.

Using a HELOC for Down Payment and Rehab Costs:A HELOC can be a great way to access equity for new investments, but taking out nearly all the equity on your SFH rental could pose some risks.

What I'm saying is that the people with cabins that are zoned to be rented via STR programs are already doing it - whether they're doing it themselves or using a property management company out there. 

This will be a property that I am using as my primary. 

In my opinion, you're better off just using a cashout refi and then parking the money in a MMA/HYSA or rolling 30-day treasuries than using these hybrid LOCs.

(Sometines using a conventional loan) Short-term pain for long-term gain2.

Not a collection agency, but have you considered using a rent reporting company to report the debt directly onto their credit reports with the Credit Bureaus? 

Also, be cautious when using a HELOC as a down payment on your next property.

I lost the info about getting a mortgage using a ITIN....