So strategically, as the second mortgagor, it is only likely to foreclose on a home if there will be money left in excess of the first mortgage.

I would think most people can get above a 6% return investing it elsewhere hence I think it makes sense to keep your mortgage as is, reinvest the money into another asset that provides cash flow in excess of 6% and use that cash flow to support your higher mortgage payment. 

That way whenever you have excess money, you can pay down the HELOC but still work to buy the property now. 

Depends on your appetite for debt and desire to build wealth. 

In most instances, you likely want to get a cost segregation study.I would argue that maybe the only instance that you wouldn't get the cost segregation study is if your losses already bring you to a low tax bracket.I.E. you are making $100,000 and your STR losses without a cost segregation study are like $60,000.That would bring your taxable income to $40,000(or even less when you factor in the standard deduciton).It would be okay paying 10% or 12% on that remaining $40,000 of income.The con is that if you did get the cost segregation study done, that you would have excess losses carried forward to 2024.

My background is accounting so it just seemed a little excessive but I don't have RE specific experience. 

Massive excessive government stimulus has consequences.  

Because of that, they do not limit the number of loans they will issue.The catch is, it would scale too slowly doing it that way because my bank also won't allow me to obtain more than one traditional loan per year, and they have an extremely low appetite for Debt to Income ratio.For that reason, I deal with the commercial lending side more often at this point.

One concern of carrying 2 policies on the same property is that most policies have “excess” clauses.

The Master LLC only provides funds for investment and receives cash flow from the excess income.