What you will find is they typically appraise for far less than the hands off cost to add the ADU.  

You need to develop a subject matter expertise and treat this like the hands on business that it is. 

I have a handful of SFH rentals in northern Texas.

@Steve Vaughan  when we went through the 08 to 2010 debacle and over 200 landlords handed me back their houses.. and lost ALL their money... it was an eye opener and they were all landlords all west coast based   a few on east coast.but they walked..  

Generally there are multiple units for each "zone" if you will when I've seen them installed.Regarding your problem at hand, I personally would simply adjust your plan to move and make your initial plan to get the current issues resolved, while costly now, in the long run holding onto the unit will likely pay off. 

@Jonathan Greene I have 20-30k on hand rn that I can put into a deal.

I just put together a flyer and hand them out. 

I've been investing in STRs since 2005, and I have only had a handful of items of any value that were broken, and I would rate these as probably from lots of use. 

Since you're already in Tampa, staying local for your first few deals can help you stay hands-on and learn faster.

A new construction ADU will be appraised significantly less than the hands-off construction cost.