The opinion of several investors in the market I invest in to keep things on the 15 year plan to paydown the debt faster, but I want to go to between 80-100 units (for cash flow purposes) and local banks are starting to cap me at current levels. 

I can take that money with my own marketing and database building and go further, faster with building my business.  

What could be improved upon for better and/or faster results?

On the other hand, many SFH which are newer sell faster. 

We sold it for a decent profit 2 years ago and thought, "What if we could do this again, but faster?"

Commercial loans may be faster, but they cost more and tend to be shorter.

The reality is you can figure it out yourself for sure, but I definitely agree with @Frank Wong that having a mentor is going to help you go faster and make fewer mistakes.

To maximize your deductions with bonus depreciation, it might be worthwhile to do a full cost segregation study, which will properly identify all of the assets in the property that can have a faster depreciation life.

I know I won’t be making much to anything on cash flow but would it be worth it’s weight in gaining experience in RE, tax benefits, appreciation several years later, rent increases and bankroll of a cal.

It means you can kick out a bum much faster without sitting around losing money or going into long expensive evictions