I am very enthusiastic about this grant, and strongly support accepting the proposal. Keystone’s technical approach is sound (I especially like the animated-QR-code communication channel that obviates concerns about potential exploits from the host computer via USB or Bluetooth), and their stack is built almost entirely in Rust, which greatly increases my confidence that this will actually result in secure and usable shielded wallet support.
I think this has a very good chance of finally allowing the hard work we put into facilitating hardware wallets in the shielded protocol, to get into the hands of Zcash users.