I am Japanese and I find this plugin easy to understand and very easy to use, but I have a couple of complaints.

The first is that you always have to enter the command once when creating an arena.
I tried to add another configuration file directly when creating an arena, but it failed because of the specification that you have to enter the command once.

Another thing is that the only way to enter the arena is by command.
I would like to enter the arena using a sign, but since there is no plugin that supports placeholders, it is inconvenient to display the current number of people on the sign.
I wish there was a plugin that would allow me to enter and exit with a sign.

Sorry if this is hard to read as I am not familiar with English....
But your plugin is really great, please fix the above !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I'm waiting for a good reply:D