Was it advantageous?

$300 bucks spent in one hour.This $300 means WAY more to the resident who most likely does not have the advantages or opportunities that real estate have been able to provide you and your family.

An advantage of turnkey is that it allows investors to participate in markets outside of their own. 

I know it's heating up and I'd like to take advantage before I get priced out.

If she's not telling you why she stopped paying and she's not applying for assistance, then I suspect she's just taking advantage of the situation and stealing free rent.I would contact an attorney today to see what your options are and start the process.

Even a worst case scenario is still a win/win and no one walks away feeling like they were taken advantage of.

I've been looking into maximizing performance and one scenario is the idea of building or acquiring a quadplex to take advantage of lower down payments / lower interest rates of a residential mortgage but then layering this with a max value rent by the room strategy.In many places it seems you can have 6-8 unrelated individuals in a home.Is anybody maximizing these joint strategies by building out a quadplex with 6-8 bedrooms per home and then renting out per room?

The advantage would be being able to eliminate flood insurance and have a larger profit margin.

If something happens to them the business might fall apart whereas the larger business they just place another doc in the network for that location and business as usual.You could just wait until other tenants offer on the property or wait in general to change the lease terms to be more advantageous to you with these tenants.You need a commercial retail attorney on your side for the lease negotiations or a lot of mistakes can be made.  

With $20K, I would try to find something you occupy so you can take advantage of the low downpayment loans.