Personally, I feel as though it was very lucrative back in the day, but it is much more difficult now to see a great return on a STR post-covid due to a saturation of people wanting to become STR owners, municipality restrictions, etc. 

Small businesses allow more discretion because the owner is a hands-on decision maker in the day to day operation.

Also community rules, rental restrictions, pet restrictions, occupancy restrictions - anything that could interfere with your operations. 

If it is owner occupied then hard money lending will not work as they will not touch owner occupied then the route would try and be friends and family. 

They’re on a m2m agreement, previous owner didn’t have an issue with them or any late or missed payments ?

What are rights of owner vs tenants if new buyer wants to occupy one of the units as a condition of purchase?

Here are some considerations for investing in a duplex in the Dallas area and potential alternatives:Investing in a Duplex:If you rent out one property, you can possibly create positive cash flow by partially offsetting your living expenditures.If you're an investor with limited funds, duplexes could be a more accessible alternative because they may have lower entry expenses than bigger multifamily properties.Perform in-depth market research in the Dallas region to pinpoint communities that have high demand for rentals and good prospect for real estate growth.Take a look at owner-occupant-friendly financing choices including FHA loans, which frequently have less down payments.Make sure you have a well-defined escape plan.

However, finding a single-family home (SFH) with existing tenants who are open to an owner moving in might be a bit challenging.

In Illinois it must be a licensed plumber for non owner occupied properties. 

Many owners foolishly waive this for S8 tenants.5) Time remaining on lease (many owners dump their properties when they find out existing S8 tenant will NOT renew their lease)We currently manage almost 100 S8 leases in Metro Detroit area, so we are very familiar with all this.