Hey Simon!
As another user of Trisquel's accessibility, I'm glad to hear from you,
as is the development crew, I'm sure. I don't think you need to worry
about the acceleration, as the classic view is the 'norm' for this
distro; if you were to enable 3d (assuming there's support for your
hardware), you wouldn't find yourself switched to Unity or Gnome Shell
without your consent:). I installed a 5.5 Beta on the 12th or 13th,
onto a netbook, and have upgraded orca and libreoffice for better
accessibility, especially to libreoffice calc, which I found almost
unusable in 3.4.. It looks like the remaining accessibility bugs are
those in Ubuntu or Debian packages, and not things Trisquel can fix. I
look forward to more observations from you, as you continue to use and
explore the Trisquel betas.
Cheers,
Dave