Well, it's up to trainerlord. Because it's still his plugin. I'm planning to do a new plugin, however i'm still learning to code in the right way. In that time i'm just updating this plugin to never minecraft versions.
Any way, to player rename them world ? i need to give them an option for change size of them worldborder , but , the name of world is : 2e156sfe-2s4fee54fes-fes5484fsf-654fe-5fesfse54thf-jyg4gy864 ( is an exemple )
If you want to add them before, you can try to use the World Template feature. With that feature you should be able to create a world and use it as a template for creating worlds.
I don't know other ways to do it, because it was never intended to use custom blocks.
this plugin would be very popular if it's used like the server OriginRealms, i'm afraid to make it permanent on my server and bugs not get fixed lol this is the time i wish how to code