Wonderful plugin with very good functionality. But does the developer still monitor the project? If so, you can fix an issue that is changing the default behavior of funnels (as seen in the vanilla item sorter)

It's Pretty Good Plugin So Keep it Going and Usefull to sort the items and i will keep using this plugin

Very unique and interesting plugin, I didn't expect to see such a thing :D I hope this plugin will continue to be improved and will not be abandoned :-]

solved the error sorry for modifying your plugin just modify the plugin.yml inside the .jar changing these 2 lines and it is perfect

api: "1.20.1" and api-version: '1.20'.

error in server paper 1.20.1, I see a great future for this plugin.

[18:54:21 ERROR]: [ModernPluginLoadingStrategy] Could not load plugin 'extend_hopper-0.1.1-spigot.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: Unsupported API version 1.2
at org.bukkit.craftbukkit.v1_20_R1.util.CraftMagicNumbers.checkSupported(CraftMagicNumbers.java:380) ~[paper-1.20.1.jar:git-Paper-45]
at io.papermc.paper.plugin.provider.type.spigot.SpigotPluginProvider.createInstance(SpigotPluginProvider.java:119) ~[paper-1.20.1.jar:git-Paper-45]
at io.papermc.paper.plugin.provider.type.spigot.SpigotPluginProvider.createInstance(SpigotPluginProvider.java:35) ~[paper-1.20.1.jar:git-Paper-45]
at io.papermc.paper.plugin.entrypoint.strategy.modern.ModernPluginLoadingStrategy.loadProviders(ModernPluginLoadingStrategy.java:116) ~[paper-1.20.1.jar:git-Paper-45]
at io.papermc.paper.plugin.storage.SimpleProviderStorage.enter(SimpleProviderStorage.java:39) ~[paper-1.20.1.jar:git-Paper-45]
at io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler.enter(LaunchEntryPointHandler.java:36) ~[paper-1.20.1.jar:git-Paper-45]
at org.bukkit.craftbukkit.v1_20_R1.CraftServer.loadPlugins(CraftServer.java:504) ~[paper-1.20.1.jar:git-Paper-45]
at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:273) ~[paper-1.20.1.jar:git-Paper-45]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1101) ~[paper-1.20.1.jar:git-Paper-45]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:318) ~[paper-1.20.1.jar:git-Paper-45]
at java.lang.Thread.run(Thread.java:833) ~[?:?]

This plugin is very good! But we need a English description since it's more common for us to understand.
Have you tried to add multi-language? I'm glad for contributing a Simplified Chinese translation for your resources.