Just remember if you sell it, make it your primary again by living in it for 2 years, or buy a new property using a 1031 to avoid capital gains.

How can I find a list of homes that are not currently for sale but that may have an ADU, so that I can start to reach out to these owners about any potential interest in selling?

I'm a part of partnership that attempted to do a flip in Fl, but due to market conditions, bad contractors and multiple change orders, etc....looks like we'll be selling at a loss. 

Jack Bosch and a lot of the land flipper guys who teach it like to have their students buying in the high deserts and remote areas of the Western US  or in FLA like le High Acres etc. this is were cheap land is and land that gets traded constantly at tax sales.. the play for most of them is really simple.buy at tax sale or with direct mail.. for a few grand  re-market them for more and sell on terms and collect monthly payments.. 

A seller called us back and wanted to sell this property, made more sense to flip it.

Some lenders hold there paper, some sell it, some do both.

Many bought in 2020, 2021, and early 2022 who are now being PCS'd out of the area and have to sell a home that has dropped in value over the last 18 months. 

Plan to sell all POHs, seller financing, or cash sales.

I called about 30 investors in the area asking if they would be willing to sell.

So you figure 25k for a down payment equates to a property worth about 166k that will need maybe 75k in repairs let's say for a total project cost of 241k (loan amount would be 216k approx), then holding and closing costs of about 15k.Now when the project is over and you sell, you'd want to try and sell it for 241k/.70 = 340kish.