Default

"permissionName": "zlevelsremastered.use",
It is added.

That isn't something that should be in the configuration; just makes it prone to breakage. Prefix will be forced soon, so if they customize it to remove that then it will not work.

Default

It was placed in the config before I took the plugin over, I'll go ahead and move the permissions to be hard permissions, or just set the prefix and let the user set the permission name itself.

There isn't really a reason to have it configurable, just leads to confusion and issues.