I'll help you if you promise never to look to commercial lenders as a source of advice again. They have lots of opinions, but they rarely actually know anything.
Bankers who are just now starting this project (there are plenty) should note the reference to "Massachusetts" business trust above. Any requirement for a trust to register with the state would be specific to that state. Then, they should go to the website for their state's SOS. Wade through the registration process, look at the forms, etc. Oftentimes states assume the user of the website is setting up a business and needs advice about what types of businesses are available. So, they include a list of possibilities. Here's the
cheat sheet for WA. (No trusts.) You have the incentive to learn about each type of business entity and make your own decisions based on real research.
Develop a list of entities required to register in your state. (It will not include trusts, but you need to add general partnerships.) Give it to the people who open new accounts so they know when to look and when not to look. In candor, the CIP process should have given your new accounts people some insight into what types of entities are required to register, but they still need your list to know when to get the beneficial owners'