Tweaking the Thinkpad's TrackPoint settings in Linux Mint 19

With the update to Linux Mint 19 Cinnamon, the sliders controlling the trackpoint's accelleration and speed on my Thinkpad T560 and T500 don't work any more.  I expect it will get fixed soon.  Meanwhile, as root I  can manually edit the parameters in the filesin the directory

• /sys/devices/platform/i8042/serio1/serio2

The above directory is found by

• find /sys/devices/platform/i8042 -name name | xargs grep -Fl TrackPoint | sed 's/\/input\/input[0-9]*\/name$//'

Settings are reset at reboot.  :-(

I like sensitivity 125 and speed 80 on the T560; 190 and 90, inertia 10, on the T500.

Update

I found this solution (X1 parameters) that automates everything and survives reboot :-)

Another update, March 2020

Lalufu at github said,

You can also use xinput to modify the libinput values directly:
Run xinput to show the pointers the system knows about. If you have a ThinkPad you should see something along the lines of TPPS/2 IBM TrackPoint or similar.

xinput --set-prop "TPPS/2 IBM TrackPoint" "libinput Accel Speed" -0.5

will modify the pointer speed. Play around with the value to see what you like. If you want this to survive a reboot you can stick this in .bash_profile.