I completly ignore FINCEN regulations and I encourage everyone else to do the same.
lol I remember the "Pet Rocks" they were actually a thing when I was a kid and people used to actually buy them.
FINCEN issued guidance. None of his has actually been tested in a court of law yet. Ignoring until there are clearer legal cases and precedents seems a reasonable strategy for an individual, perhaps more risky for a business.