Is your feature request related to a problem? Please describe.
No, it would just be really useful for Litematica to ignore certain air blocks, and not tell me that it is an "Extra" Block.

The only problem I can think of is pick blocking, and especially with "executeOperation"

Describe the solution you'd like
probably do it like how Minecraft does it in the Structure Block

Describe alternatives you've considered
You could add some sort of menus to ignore specific blocks, but this would be hard to navigate (The only good side is, you could specify which block blocks to flag and which block not to, so you could, for example, only allow stone, cobblestone, and mossy-cobblestone)

Additional context

• Structure Void
• Structure Block
• Video about it (Not mine...)

just ran into this also! Would be helpful to avoid the dreaded pink outline for air blocks I know are inconsequential