is there a way to store data to a block/location without a tile entity?

hey, this is my first post and I want to make a nation/empires mod. My idea was to store wich country each block belongs to in a custom nbt tag for said block. The problem is that this needs to work for every block, including grass, air, stone, etc, and NBT tags only seem to work for tile entity blocks (not most blocks' case). So I was wondering if there was some other sort of way to store data in a block, or even better, an XYZ position, that would be independant of what kind of blocks there were. Thanks in advance.