In practice, as long as a definition can conceivably cover something, the DOJ or some agency will use it. Case in point from yesterday: money transmitter as applied to arresting the developers of a NON-CUSTODIAL wallet, as part of a wider war on crypto mixing:
https://www.coindesk.com/policy/2024/04/24/samourai-wallet-f...
This comes amid a war on end-to-end encryption, and so on. It's not like they are going to stop here.