UTXO has to be signed by both current block and previous block set of nodes
If so then how a tnx to be instant confirmation as your spec if it need to wait one more block sealing; as you know block sealing by PoW take times.
It is instant, you don't have to wait for new block to be mined. "Current block and previous block" means "lastest block and the one before it", I might need to clarify it in the paper. Thanks.