The reason some blocks might be missing is either a) you don't have all the mods installed, or b) when the materials list has multiple entries for e.g., "Oak Planks", it doesn't mean Minecraft's "Oak Planks"; it means Chipped's "Oak Planks". But Chipped has many blocks named "Oak Planks"!
To figure this out I had to dig into the .nbt file and look at the item ID's in the palette section.