I have watched a very nice video where I saw a girl use a Braille display. In the video she quickly shifts either the right hand or the left hand over the degradable keys.
I haven't watched it carefully, or perhaps I just don't remember proper, but it seems to me that one can either use one hand to navigate the entire length of the keys from beginning to end, and then press a key to refresh all of the keys, or, use one hand to read from start to a certain point, and then with the adjacent hand, place one finger next to the other and trace the rest of the display with the other hand.
I was wondering, would there be any use, in practice, to refreshing the Braille display only "partially"?
By this I mean, instead of the plastic pins going down and the new ones coming up for the entire next set of Braille letters, could you force, say, the right half of the Braille letters to sink and appear over the right half of the display, and new, succeeding keys, to appear on the right side of the display.
Would this be useful, say, if one wanted to read a particular set of contiguous keys on the display, deciding word boundaries, all at once?
Is this need, on behalf of done users, for reading everything together (e.g. The proof of a complex math theorem), the reason one would want an 80 key display as opposed to a 32 or other shorter length display?
If the display is X = 80 keys, can I advance the display by N = 8, 16, 24, 32, etc. number of keys at a time, or n, with a custom braille display key advance granularity of M = anywhere from 1 to 80?
For me, who has never touched a Braille display, it is a long standing issue I still fall to understand.
P.S. I know, on at least done Braille displays, there are the keys to the left and the to the right of the display keys. Not sure if these are left/right display shifting keys with a granularity of 1/3.