Reaction score: 229
moused_flags="-V"gets trackpoint+middle button scrolling to work as intended.
hw.psm.synaptics_support="1"makes everything work: all 3 trackpad buttons + the red thingy. Not that I used it much, but was proud to see that it actually works. It also has fingerprint sensor, but I didn't even bother to make THAT work. Although might be funny. Even without moused_flags.
catthe corresponding input devices:
# cat /dev/input/eventX