Very cool. Reminds me of an excellent radiolab I listened to about Wubi: https://www.wnycstudios.org/podcasts/radiolab/articles/wubi-...

If you can effectively type 70,000 characters with 26 keys, certainly you can type 26 characters with 5 keys. It would be even easier if you made it two handed.

(In other words, I think this could someday be a practical text input method)