Since many of the servers use lobby just for transportation-related stuff, I think it would be better to disable all unwanted things that could reduce lag. For example...removing all particles, setting world borders so that terrain generation is limited etc. I am not sure whether I'm right or not. But I do know that the last time I deleted src/pocketmine/level/particles, it automatically regenerated the folder (obviously because I'm such a noob when it comes to PHP)! The question is, will deleting the particles and making the world limited reduce lag or crash the server? Also, are there any other ways to reduce lag?
Disable hunger by using attributes. (I am not sure how, but I somehow did that. I discourage anyone else doing that because it appears that the attributes API is not stable yet)
Katana adds a variable to the Player class that declares weather hunger is enabled for that player or not, you can just disable this by setting it to false.
Katana is only for big minigame servers,, and it does not support Android and Windows. Make sure you know that before trying to use it.
I quite don't get it but I don't use the 'PocketMine-MP.phar'. I extract it and use the 'src' folder! It's much easier to edit and stuff...