There are a number of articles regarding digital mode use by the blind at:
hamradioandvision.com
As for fldigi, it isn't screen reader friendly as you already know.
I looked at it a few years ago, but couldn't make much out of it. I do
some RTTY using MMTTY.
Digipan lets you set a menu that allows use of the left and right arrow
keys to jump to the next signal in the waterfall.
73, Steve KW3A