I love seed XOR as a backup.

You can do 2, 3, or 4 splits, but 2 is recommended. For example, you have a 24 word seed. It gets split up into two 24 seeds. You need part A and part B to build the actual seed.

So if you could somehow get 3 seeds on steel, you would only need 2-of-3 steel plates. You would not need the descriptor as long as you have 2-of-3 plates.