Forget about fake-xinerama-screen, THI is here!
The new mtxdriver 1.4.3 compiled flawlessly on my system and let itself
install flawlessly too (except one typo in the install.sh file, see attached
patch below).
Since I got my third TFT I had the problem that the old driver wasn't capable
of driving three Displays in independent mode. The only window manager known
to me who can handle this is enlightenment v17 with the command line option
fake-xinerama-screen.
Before 1.4.3, I used the following command to start my window manager:
/usr/local/bin/enlightenment -fake-xinerama-screen 1280x1024+0+0 \
-fake-xinerama-screen 1280x1024+1280+0 -fake-xinerama-screen 1280x1024+2560+0
With this setup I had virtually three independent screens in terms of
maximizing windows, showing started applications per desktop, etc.
With the new THI option everything works like I was used to when using
DualHead Independent mode

(check out the xorg configuration file below)
Update:
Now there is an installation package instead of the two fix-typo patches!
Downloads: