This type of banking is a specialization that is referred to as "low documentation" by bankers. It exists in areas with large migrant worker communities like California and Washington.
It is innovative and profiable, but extremely difficult in the post 2008 regulatory climate. I know bankers who work in this industry. The commentary I have heard is that the regulatory burdens are severe.
If you don't have the endurance for being incorrectly threatened with fines and crimes which you have to successfully prove wrong, you won't survive.
It sounds like gambling with stakes that exceed my risk tolerance.