I was bored one night so made a bash script to toggle mouse acceleration for mac.
It works by using the command:
defaults write .GlobalPreferences com.apple.mouse.scaling $val
The only issue with this approach is that your mouse sensitivity will be locked but since smoothmouse.com is no longer supported, and I could not find any free solutions without ads or prompts to pay for the full version, I decided created this as any easy way to toggle it on and off.
If you don't know how to execute a bash script - you can't go wrong with this guide.
mouseacc [-r | -w [-1|1] | -d]
options:
-r, --read read the current value (-1 = off, 1 = on)
-w, --write set value (-1 = off, 1 = on)
-d, --remove-setting remove the mouseacc setting and use system default
Also a reboot/loginlogout is required for a change to take place.
Enjoy!