I'd be willing to give it a try. Have you done any work on the hand movement model, like he shows at 2:06 in the video you posted? Mine would be different from yours, since I type with just one thumb.
The important part is how much time it takes to type key 1 after typing key 2, right? Maybe just logs of people typing with time stamps for every key or something? Then I could make a map to teach the AI with.
Are you particularly attached to the evolutionary algorithm? I might try a few different ones.
Oh it looks like MessagEase has. I should've looked at their paper first.