The point of the account was multiplayer, unfortunately. Wanted a locked down account to play the game with a closed group of friends.
Ended up on Minecraft Education on the computer, eventually.
Closed group of friends works fine in offline mode (pirate friendly mode).
If you can get a group of other parents to also pirate...
Not really in the cards, though I can appreciate your dedication to pirate advocacy.
The referenced config setting is apparently literally just whether to have the server authenticate accounts with Microsoft, so pirate and nonpirate players can play together on a server with checking off.