MATE control center Mouse pointer speed does not affect to ThinkPad T420 trackpoint speed/sensivity.
1) if UltraNav touchpad enabled - the touchpad speed and sensivity changes (all right). Also if qsynaptics installed - it works too.
2) if touchpad disabled in BIOS - only one pointing device enabled. MATE Mouse speed does not change speed/sensivity. qsynaptics reports error (no touchpad found)
Another machine (tinkpad x220 and t420 with same ultranav and altlinux p9 sysv starterkit with xfce or lxde/lxqt - trackpoint settings works good)