Additionally, it's easy for a house on one lease to get absolutely trashed by the renter.

In addition, I presented his was not the usual use case because he was unleveraged.  

Furthermore, whole note investments benefit from an additional 0.5% annualized yield and are entitled to a share of any extension fees charged to the borrower."  

I pull permits for removal of load bearing walls, addition of bathrooms or bedrooms, addition of footage.

I agree with the others here that say you need to have some skin in the game, if you are going to live there yourself, get an FHA loan rather than owner financing, you can get a 3.5% down loan, personally I do not love these as they require  PMI which is an additional expense, and you also need  bring additional funds for closing at least for taxes, title, attorney and transfer fees . borrowing from anyone else for the down payment, to include a personal loan from the bank is not a good idea, those again will be higher int. rate.

If you can add a legal ADU at $25k in the Austin area then you should add it.  

Additionally, there typically are additional state protections (outside of the agreement) based on where the fund is located.

Considering that, you are likely going to see appreciation year over year, which essentially will be additional equity you'd capture just by simply living in the home. 

If the price was right on Turn-key maybe, but probably more of the fixer-upper that can be leveraged later on for additional property or sold for a nice profit. 

Minimal changes to effect common entrances, no major shifts in load bearing, easy plumbing changes for wherever the new kitchen would be... it's a lot of boxes to check.