Not an issue, just a question. Is there currently a way to add a one-time command? Not temporary permissions, but where a person gets access to a command to use it just once.

Not really possible, permissions aren't bound to commands only, but plugins can check for a certain permission anytime, when moving around, doing certain actions, running other commands, even when showing up command suggestions while typing them in chat!
While this at first seems like (and would be) a great idea at first, it isn't really possible due to the nature of "permissions are not always for commands, they can be checked at all times".

Thanks for the response. Should I understand, then, that the only way to implement this on a server would be to integrate this functionality into the plugin that manages the command?

Correct, it would be up to the plugin author to implement such feature, as they are the only ones that can fully control when the action is completed successfully.

Alright, thanks.