When I finally figured out how to make the background totally opaque in the full screen composition, I gave up using Byword for doing my first drafts. There are couple of things that I still like in Byword of which I wish I could take advantage in Scrivener. As far as I know Byword doesn’t do any spell checking. which I prefer when composing. After I finish, I copy to Scrivener or another app to make the corrections. In Scrivener full screen composition mode, it’s distracting to see the red underline. I can’t resist going back to make corrections to make the distracting underscore go away. I would like to see and option to turn off spell checking in full screen mode. I know I can go turn it off in the options, but then I would have to go back to turn it back on when I was done. Having an option to surpress it in full screen mode only would save several steps and perhaps the assumption that I spelled everything correctly for once. I’ll post the other wish separately. My apologies if I missed this option. I did look through the appropriate options tabs.
P.S. I use the OS X version