If you want your server to be here, just dm me ! 
it is not a lack of will 1.18 remains my favorite version. This is impossible because in these versions of Minecraft, you cannot stop a sound from a resource pack once it has started. Which spoils a bit the principle of BattleMusic. However, MCJukebox and NoteBlockAPI still work in this version, so if you use MCJukebox and NoteBlockAPI the plugin should work fine. So you can use BattleMusic in 1.18 to 1.11 but not with resource pack sound.