I am part of an effort of getting the Kaktovik numerals into Unicode (https://en.wikipedia.org/wiki/Kaktovik_numerals). As you can see the system has 20 digits with a featural composition.
One of the questions I was asked, is what way would be the best way to input these numerals (assuming new assigned code-points) using regular keyboards. I understand that there are tools called Input Method Editors, but I want to know what input method would be the most intuitive to the users. All I can say is, that a system that uses 1 key for each of the 20 digits isn't practical.