I agree with that method. I had at one time arranged the numbers, letters and punctuation in an arrangement which required the learner to wait until the entire character was sent. In some methods of instruction there were shortcuts to getting the character recognized correctly, like if no letters or numbers were introduced with dashes except the letter O, the learners (students) wrote down O as soon as the first dash was sent.
I did a lot of work on this, but I lost my system of character introduction during a house move.
73
David N1EA