• currently, addons can't add their own classes to PLOT_CLASSES
  

  Applied-Energistics-2/src/main/java/appeng/server/testplots/TestPlots.java

  Lines 80 to 86 in 31ff9da

  	private static final Class<?>[] PLOT_CLASSES = {
  	TestPlots.class,
  	AutoCraftingTestPlots.class,
  	P2PTestPlots.class,
  	MemoryCardTestPlots.class,
  	PatternProviderLockModePlots.class
  	};

• it would be nice if addons could also add their items to kitOutPlayer
  

  Applied-Energistics-2/src/main/java/appeng/server/subcommands/SetupTestWorldCommand.java

  Lines 90 to 96 in 31ff9da

  	private void kitOutPlayer(ServerPlayer player) {
  	var playerInv = player.getInventory();
  	var fullApplicator = ColorApplicatorItem.createFullColorApplicator();
  	if (!playerInv.hasAnyOf(Collections.singleton(AEItems.COLOR_APPLICATOR.asItem()))) {
  	playerInv.placeItemBackInInventory(fullApplicator);
  	}
  	}

Probably via service-loader?