The chunks way is too hard for me to know how to do it.
However, I think it is important to identify the “hole faces” created by Boolean subtraction, and optimize the vertices for those faces (to use any of the nodes provided by the official) without changing the rest of the DiggableItem.
An acceptable indication is that these “hole faces” are simplified and changed shape due to performance-optimized operation
Here are some nodes I’m testing to get those “hole faces” ……
