Investors in these type deals look for say 12 - 14% annualized return.  

From there, you can better estimate the end numbers and work back to figure out the GP/LP  equity needed and the estimated returns.

This allows for proper retirement of assets.If a property has already been sold it may still be a good candidate for cost segregation as long as you sold the building and have not filed the tax return.

I'd be willing to bet buying an index fund would have a better return without any of the headaches. 

Non traded public REIT? 

The good subs in your area will likely have plenty of work already and may not even return phone calls.

While it may reduce your immediate returns, a good PM will help minimize risk and maximize long-term profitability.Good luck!

I would like to pull out equity from the homes to build either a house on each or an ADU (they are zoned multi-family) depending what makes the most sense on returns and what is feasible.

Just like any aspect of real estate investing, non-consumer lending at a large scale is a relationship business. 

Unfortunately, this problem waste a lot of my time that could be spent on other investments.I have used the same tax professional for many years and he is very educated, but also much older than me and it's hard for me to understand all the reasons he has expressed why is better to put the rental on my personal tax returns.