Loot Table Copy Components

I have a function in my 1.20 pack where a special compass can be crafted which points to the nearest of a random structure type. This is done by summoning a treasure map aimed at that structure and storing its position NBT, before putting it into the compass as lodestone coordinates. I've been updating that 1.20 pack-however, the "copy_nbt" function seems to have been reworked into a "copy_components" function which only allows copying from block entities. Is this truly the case? Is there no way to copy components from storage in a loot table now?