The limit on scaling is your deal flow (mine never was that good) and time it takes to perform the value add (I got fairly quick for example, my last rehab did all new plumbing, electrical, and flooring.  

Zillow and OpenDoor attempted to use software to predict the sale price of properties and their results were/are bad because their software was poor and the inherent limitation of software to deal with subjective data.

Since the contributions have to come from the business income (PM biz) it’s not likely you’ll come close to taking advantage of the high contribution limits of a Solo 401k.

Because your second year is likely (oops, I did it again) to show a net profit instead of net loss.

One of the major driving factors for increased premiums is the carrier's requirement for higher replacement cost limits on file for buildings. 

And how about the loss of tax revenues during that entire time......

Back then I was much more inclined to take a more concentrated risk with the somewhat limited capital we had.  

Quote from @Stuart Udis: @Robert Ellis Location Location Location...There is limited land supply in markets with high demand and high barriers of entry.

Exactly  its why I only respond to limited PM's.

New construction in the city limits is increasingly hard to find and increasingly expensive.