Communication is table stakes and is easy to assess.

If you want to know what they are willing to allow you do with a place you're considering buying, then reach out before you reach the closing table.

It is important to look over these numbers before you get to the closing table.

I get paid $250 per call on my knowledge right now from firms in New York and you should consider what you bring to the table 

Something else to consider is that once these properties are paid off, you could cross collateralize to purchase additional properties that fit your buy box so that you may not need to bring cash to the table for a down payment.

You are likely leaving thousands of dollars in tax benefits and cash flow on the table.

@Sean Nava  If you haven't considered a cost segregation study yet on any of your investment properties, you are leaving a lot of money on the table.

It would also help if you bring a solid deal to the table in exchange for the learning experience.

Foreclosure auctions are on the table, although least preferred due to the lack of interior access (maybe with more experience).

The FHA househack strategy is fairly common and pretty straight forward, a lot of people have been using this and/or the conventional househack (myself included) so have been on both sides of the table.