FWIW deleting an account won't block the user from coming back. If you navigate back to their profile (via direct link or clicked link, or if they're mentioned, etc.) NodeBB will just pull their account info in again.
Even then, would rather my government contract out Mastodon hosting to a company based here in the UK than to use the American Hosted and moderated Elon tool.
TIL GNU Affero General Public License it a flavor that closes loopholes that were used to extend open software without actually open sourcing your contributions.