World Generation replaces "Natural Blocks" in Structure Generation (Stone, Andesite, Calcite, ect)

Currently when creating structures, you can not include natural raw blocks in them or the world generation will replace them with other blocks such as dirt and ores. Natural blocks include all raw stones such as stone, andesite, calcite, sulfur, tuff, and blackstone.

The game treats these blocks in structures as if they are part of the natural world instead of as part of a structure.

This poses huge issues for generating structures in mods and datapacks as it prevents you from using raw blocks in structure building which is a huge limitation.

What should be done to fix this is to have structures generate after all world generation is done instead of beforehand. This will prevent blocks from being replaced that should not be replaced.