Advanced Mask Option

[CrazyCoder9]

I have been wanting to add an oak floor to my mineshaft structure that only replaces air (like vanilla mineshafts), but that doesn't seem possible without affecting how the blocks of the entire structure generate.

Perhaps there could be a mask that works similarly to the "NegatedBlockMask", except, when the block is not placed into the world, it places a different block depending on the block that would have been there (for instance, it places an oak plank in the floor if there is air there (or another transparent block), but if there is any other block, it doesn't replace the block)