But if you could divide that portion off and keep it in a different business name , if you ever sold the property , you or your heirs would always be getting a check 

Meeting that 2 in 5 of the last requirement allows a single owner to shield $250k of appreciation and a married couple to shield $500k.Unless you predict a lot of income from the MTR or you feel that there is a lot of appreciation incoming over the next three years (minus time get the property sold), you may want to consider collecting your $100k (passing GO) and redeploying that money to whatever you feel is its best use. 

If we are checking property tax records, should we not buy a home where different LLCs (investors) have owned it and sold it every 2 to 3 years?

Sold it recently to make a nice profit.

I also have a contractors license and I am good at seeing value but I’ve never sold anything.

It's been cut up, sold off and dispersed through the generations but our little piece is still where I like to call home.

In other words, I expect low, if any, appreciation over the next few years.A similar investment in the S&P 500 would have yielded a 25% return if sold today.

You don’t want small condos that are easily carbon-copy for example as you have no way to stand out from competition and it becomes a race to the bottom.

For instance my 90 lot subdivision at one point I had 90 legal descriptions and parcels on one master deed.. as I sold them off we just deeded them out separately.. its super common especially in older platted cities were lots might have been small like 25 X 100 and someone bought 3 of them and then built one home on all three.. some places they force merge them others you can go back and recreate the Old lots of record.. there is millions upon millions made by those that know how to find shadow plats and bring to life underlying parcels.

@Jesse Conrad Feel free to DM your email and I'll send you a copy - which also goes for any others interested in the tool.