Such a review of yours is just what I've been missing, great job!
In fact I have a new experience to post today
I decided to try this out on VMWare, and I got it working! I had more trouble getting the system to work in general than I had setting up the magnification, but now everything works quite good. Performance is very bad of course using this in VMWare, but the fact that I indeed got it working at all was a little surprising.
While editing xorg.conf and such I used ZoomText, which worked quite nicely, except that mouse tracking was a bit inaccurate.
This is just awesome!