Checked there @BAKCYL, and it does not disable it. To check if its disabled, on a terminal type:
xinput list-props {1..50} 2>/dev/null | fgrep 'libinput Accel Profile Enabled ('
You should get something like
libinput Accel Profile Enabled (300): 1, 0
Where the last two numbers are adaptive(acceleration) profile and flat profile. For it to be disabled you want a flat profile, so the numbers should show off as 0, 1.
GNOME3 on flat profile and GNOME3 on default profile.
ElementaryOS on flat profile and ElementaryOS on default profile(ignore the first terminal answer I forgot to delete it lol).
Searching around I found a link of an old topic talking about how the sensitivity option in pointer speed is really the acceleration threshold. So it would be nice to fix the naming and add a sensitivity option. @Bill_MI that solution still working?