I knew there were some HML lenders that did OO, but OP credit score “isn’t great” (which likely means it’s poor) and “technically don’t make much money” (which likely means he has little income).i think it is long shot any HML that does OO will take on this risk for what they can legally charge for OO loan.  

I have two banks that have done so as well as a credit card, and know of a couple of organizations that have as well.

Interest rates and cap rates change, competition changes, your PM ends up being horrible, lots of variables.Just to throw you a monkey wrench, in your killer spreadsheet does it include the credit score, income, and employer of every resident? 

My goal is to wholesale some properties single and multifamily to build some capital while fixing my personal credit and building my business credit.

Once I sell that I’m gonna convert to a fourplex and do the ADU.going through cash quickly and also using credit cards when possible like to purchase materials.

If it is a credit/equity line, you could provide a lender letter that the funds are available immediately for funding - and cured any recission period. 

@Robin Simon I completed a refinance with my credit union at terms of 3/30/75 @6.85% I will have the renwal in 2026 and hoping rates come down a little by then.

How much of a credit do they offer at closing to cover the servicing fee?

With the exception of building a trailer on the property (these are hard to finance), this sounds like a good plan AND if you are using it for your business AND your business pays more than 50% of the rent (if you have more than 1 tenant), then this is a more financeable property in the eyes of banks and credit unions as it would be consider a commercial "owner-occupied" property. 

Usually the numbers don't work to build in these neighborhoods, unless government tax credits, etc.Do you see the problem with your two statements:"The turnover costs could/will be high"and"How much more damage could they do?"