Hello, 

since the new 1.21 update has a few new blocks I've compiled a list of events that could be added to the spigot API

• Listen to block broken by projectiles: currently we can listen to blocks being destroyed by players, buring or exploding. Decorated pots can also be destroyed by projectiles, however there's no event to listen to this specifically.
• Crafter crafting items event: the current PrepareCraftingEvent only works for player crafted items. I don't really know if this is intentional or a bug, if that's not the case we could use something similar for the crafter!
• Vault starts dropping items: this i pretty self explainatory, this event could allow players to listen to vaults dropping items and edit the drops.
• Trial Spawner starts dropping items: just like the previous one, this is self explainatory.