Everyone able to construct a word, knows the sequence of the alphabet. During auditory scanning, this is favourable, since the user is aware when the desired letter will be announced. Unfortunately the most commonly used letters are not in "alphabet order". This could be very annoying to a user of SWAN with excellent mental acuity.
letter frequencies, sorted alphabetically
In order to accommodate these folk, it's planned to have an option to scan through the alphabet in statistical order.
letter frequencies, sorted by frequency
Also, I'm experimenting with grouping of letters, to enable even faster selection. Text prediction is also possible, although beyond my software capabilities.