This was a post on facebook:
Hi all, and I hope you don’t mind my post, but I am a passionate cyclist, but being completely blind, forced to be a Stoker on a tandem, and most of the time limited, completely dependent on others to pilot me… Which is why I have joined this group and exploring all options for virtual cycling. I rely on technology for most things in life now, which is why I am able to use Facebook, and accomplish most things online … But unfortunately, the zwift platform appears to have done nothing to accommodate visually impaired, blind users. I was a software engineer for 15 years, and know that the simple addition of audio tones to indicate being overtaken, or overtaking another rider, or sounds to indicate the start of descents or climbs and a facility to automate announcing power numbers could easily be implemented and configured. Search in the Internet, I have send another forums evidence that other blind people have been trying for over two years now to get some kind of commitment from Swift to begin to accommodate blind users… Nothing has been done, and so my post today is simply to ask if anybody is in a conversation with Zwift, customer support at any point, could you just try to advocate and encourage them to make amendments to stop excluding the blind community from the virtual cycling world! As you can imagine, in the absence of aTandem Pilot, the virtual Cycling world would be an ideal substitute for blind cyclist, but so far this isn’t happening.    to  
Even more ideas:
Some ideas i can think of to hand under visual accessibility settings include.
Audio countdown of timer clock on start
Audio cue of distance to end point
Audio cue countdown to sprint/kom sections
Possibly a sliding scale pitch audio cue when getting in to draft/ losing draft.
Obviously audio cue over each map, garage, settings for bikes, wheels etc.
Maybe an average power watts/ watts per kg cue every 15 seconds.
Audio for power up received