I'm also very interested. Also, why cashu as opposed to lightning? Does it solve a specific problem, e.g. is the TX more condensed? Can you explain why four messages were needed? 

 Because the #cashu message itself is the bearor token, it can be instant, partially offline, and zero fee. 😎 

 This is really cool. I'm inspired note1p6gnzxkm0n9dh2c6clplnswzc9gy4krqrlpkw5j9ud5q3j559xrs9rcuek