I was really surprised to find that dot i/o didn't teach the 2 character chords first, then move up to 3 character chords, then 4, 5, etc.
I like that there is a 'custom' option to do this, but it feels so natural to set it up that way: the chord-timing for a 2 key chord is easier to find than for 3 or 4 keys.
Repeatedly succeeding at the beginning for a new user is imperative. It would increase ease of adoption; and therefore increase adoption success, and decrease abandonment of learning.
P. S. This sort of process improvement is what I do for a living, and this bothered me enough to work for free, lol. Feel free to dm me if you want to validate the data.