In singleplayer, you can type really long messages/commands (I think it's infinite, but I'm not sure) On multiplayer servers, however, there is a character limit. Would it be possible to have capability with infinite message lengths - in multiplayer? If there is, would you be able to only allow this feature for players with a certain permission? Note: I'm not requesting a plugin, just asking if it's possible.
This is not possible. As far as I know The length of Your chat is also limited in SP since it is The exact same cliƫnt.