As the title suggests, adding an option for decay in blocks.
Basically trying to emulate what vanilla leaves do when a player cuts down a tree; many MCreator modders I've seen have been looking for a way to do this, to avoid floating trees. I feel this could be implemented in the block creation element editor with a check box and (if checked) setting which block acts as the "wood" for the given "leaf". I hope that makes sense.
Also I'm not sure if I'm blind but if adding above isn't possible then perhaps adding a a component that checks in a radius around a block is? That component by itself would make emulating leaf decay a possibility with MCreator, as one could just make it so a block checks a given radius around it for another block, and then staying spawned in or decaying from there. The [get block] component kind of does this, but only checks at the given xyz location rather than over an area to what I've experienced using it ^^;