A lender advised me to take out a HELOC against one of my properties (San Francisco Bay Area) and pay cash for a future rental to avoid the high interest rates now and be favorable with sellers.

The property was sold back in 2010 to a company and two other petitioners.Moreover, I found an appeal document dated Oct. 2021 in which the company (buyer) is trying to appeal from a decision that awarded prejudgement interest in favor of the intial owner.

Then that split will favor the LP because you got some profit upfront as well. 

If I can get a deal that'll incorporate it and it'll work in my favor than maybe. 

Credit scoring is being reviewed by our government, as it can be manipulated.In this time where rate may mean a no go verses back in December when a borrower's debt to income ratio was more favorable, understanding each piece is important.The actual "hit" depends on number of months history of paid as agreed and types of credit used.

The federal government comes out with specific tax laws and it is up to the states to conform to the tax laws or not.California, unfortunately, is a state that does not conform to a lot of the favorable federal tax laws.

Economies of scale work in your favor because if one tenant moves out then it has less impact plus there is only one roof and still four walls.

Apartment communities still get favorable pricing and many have HVAC certified techs on staff; so, it's exponentially more efficient than SFR.

From What you described - it seems like this deal favors the owner heavily and places an exorbitant amount of risk on you.  

Real estate is your way to stack the odds in your favor