They were all non performing - many renovation loans where little reno was done and maturity date already passed - guessing it was inexperienced borrowers learning how to flip and were getting "easy" money. ya they took me out of about 14 of my deals and well being that I was getting paid it was not my place to coach them they made loans far in excess of my positions. 

There have been multiple break in attempts, one successful on one side.

The successful wholesalers I know spend $8,000 + per month on online marketing, SEO, SEM, landing pages, lead conversion, etc.  

@George Turner Alpine Building Performance is another great option!

This has been crucial to the success of getting in paid in full by so many tenants.

Build to rent (BTR) is being performed by various developers in various markets.  

Quote from @Joshua Wei: Can anyone recommend a company in or around Birmingham, Alabama that performs cost segregation studies for single-family homes?

I've had LOTS of success in refinancing BRRRRs with small to mid-sized banks.

The best way to get a good contractor in my opinion will be to ask for bids on what they perform.

Brands like DeWalt, Milwaukee, and Makita are highly rated for durability and performance, and they often have good discounts around Black Friday.