In Arkansas, you have to drop your appraisal license to do evaluations without conforming to USPAP. I know several people who did that. One does commercial evaluations for $500 each.
For banks, the issue can be that if you are holding collateral with evaluations and the bank gets in a tight spot, the examiners can require you to revalue all property with a bona fide appraisal. I and my assistant kept busy in 2008-10 revaluing existing loans for 2 banks on the FDIC's naughty list. I had some commercial property valued at $100,000 by the in-house evaluator that I appraised for less than $30,000. I saw banks talk someone into taking over a failing poultry farm at 100% LTV only to see farm values fall and the bank have to repo them even though the borrowers had never missed a payment. It was a bloodbath for both banks. One bank was literally at the point of failure when another bank bought them and the other had an associated separately chartered bank in Oklahoma which raised investor money and merged the two banks. The board of directors of the bank in trouble were forced to resign and banned from banking for life. Another loan officer was banned for life and fined $5000 for making a loan that he was forced to make by the board. The property involved was a huge poultry egg complex of some 10 barns. The guy was failing largely due to back injury but they extended a loan beyond the value of the properties so he could process eggs as well as run the layer operation. This worked for a while until the egg prices dropped, and he folded up. He lost his farms, and they sold for about 15 cents on the dollar. A couple of the farms never returned to production and serve only as hay barns.