Great stuff. I can't believe people are still making HW wallets without screens. If you can't see it, you can't verify it!https://twitter.com/saleemrash1d/status/1067123746799001602 …
That said, their approach (establish a channel to the user's smartphone and use its screen) would be great if it could be done in an obviously-secure way. Lets you write most logic+UI code on an established platform instead of a bespoke one.