Modular" homes do have many of the value points that you state in you post in that you can generally have you modular built faster and cheaper than stick built.I am in the middle stages of vetting modular companies here in Texas and will be working to build out several modular duplexes on a piece of land I have identified, jut working with the county engineering team to verify infrastructure.

Or should I  move to a market with lower barriers of entry and look to scale up faster ie.

Or do you want to scale much faster and quit your day job? 

One suggestion for your analysis is that you can expect the Raleigh market to appreciate faster than inflation based on population growth, stable economy and businesses, and lots of media attention as a top city to live in.

I'm trying to grow the money faster by putting it into a rental.

It's on the I-85 corridor between Charlotte and Atlanta, and the factors that are fueling growth in those two cities are also driving economic growth in Greenville, Spartanburg, Asheville, Anderson, Clemson, etc., without the competition you see in Charlotte or Atlanta.  

It's a lot faster than rolling normally is, or masking everything off for spray.

Perhaps look into the Homestyle loan program that allows you to purchase with conventional financing but wraps renovation costs in so you don't have to get a 2nd or refinance to do the repairs and it can get your BRRR up and running much faster.

And you can get a mortgage, cheaper, faster and much easier by doing it in your own name.

They do start to cashflow or flow better after years of raising rent faster than costs.