If it is being sold as-is and they are only entertaining cash offers, it could be because the house is not habitable in which case a bank won't touch it with a mortgage. 

I've been searching for residential multi-families in the $1M - $1.3M range to offset my mortgage by renting out other units.

Also some lenders will offer this on newer originated loans.It’s not common but I have seen it offered on occasionIf there is a higher default interest rate then I would consider it but if it’s the same rate as default I would not accept it

There is currently $428,000 in combined mortgage debt + a HELOC on the properties.

Anyhow since I'm paying cash and don't need to get a mortgage on it should I still go through a proper title company to get it the title switched over to my LLC?  

I can also get a Home Equity Loan from Better Mortgage for another $70k and then sell which would reduce the taxable amount to about $130kCurious on thoughts from others if you would prefer to try and rent it out again or sell and allocate the money elsewhere. 

For a new property, lenders check your income, credit score, and debts.

Did he assume a mortgage on the home and then have the buyer do a "wrap around mortgage" with the promissory note?

After seeing several "market crashes" of varying degrees, an experienced lender will not lend 100%..particularly on a non-owner-occupied investment.

Chase realtors, investors, lenders, brokers.