Yes — this addon is also available for free on kunemann.com. This Superhive listing exists purely as a way to support development; buying it here is optional, and gratefully accepted.

Soft lock hides the node group's internals behind the placeholder but keeps everything intact underneath — unlocking restores it exactly as it was. Hard lock deletes the internal nodes outright once you save and reload, leaving only the placeholder and (optionally) a local backup file. Use hard lock when you're distributing a .blend and want nothing recoverable without the password.

Nodes locked with that password can't be unlocked without it — there's no recovery. If you enabled the backup option before hard-locking, the JSON backup written next to your .blend can still restore the original nodes, so keep that file somewhere safe if you use hard lock.