Nice. Ive been thinking about putting this in hardware. Generation on an air gapped handheld with a big enough display. Options to store or not store the grid in a secure element. Any thoughts on this? 

 Airgapped generation FTW 🙌  - you could even do it with Tails. See here: https://twitter.com/borderwallets/status/1567821122602782721?s=46&t=iGiWjE-xvLW1ZAQS7DVEXA. Secure elements - I don’t see why not