Leaderboard

You do not need to be messing with events at all. Firstly, I'd recommend using SoundType.CROPS rather than SoundType.PLANTS. It's a more appropriate sound type. Secondly, overriding onBlockHarvested is the wrong way to do this, and is the reason why you are hearing nothing. That method is responsible for playing the block-break effect (sound and particles). It's not responsible for dropping items and you shouldn't abuse it in this way. You shouldn't be hard-coding your block drop logic in 1.14.4. It should be done in a JSON loot table for the block now. Look at the vanilla loot tables (e.g. data/minecraft/loot_tables/blocks/beetroots.json) for an example, bearing in mind that modded loot pools also need a "name" field with some unique name for the loot pool.

Just to note, for simple data like an integer progress value, you can take advantage of the vanilla Container#trackInt() method to automatically sync values from server to client while the container is open. The vanilla furnace uses it, and McJty has a tutorial about it here: https://wiki.mcjty.eu/modding/index.php?title=Tut14_Ep5 ("Showing Energy in GUI"). But beware - despite the method's name, it will only sync up to 16 bits of data - see SWindowPropertyPacket. Shouldn't be a problem in this case, however.