Apple Magic Touchpad 2 configuration script

amt2config.sh

#!/usr/bin/env bash
# XInput/Synclient settings for Apple Magic Touchpad 2
# AGPL v3.0 or greater at your option
# (C) Leonora Tindall 2021
# Based on a Reddit post by /u/fr3lld
# and a very helpful AskUbuntu response by Jamie Scott
# Place this somewhere, set it as executable, and place the filename
# in in ~/.xinitrc

set -e

ID="$(xinput | grep "Apple Inc. Magic Trackpad 2" | cut -d "=" -f 2 | cut -f 1)"

if [ -z "$ID" ]; then
  echo "No AMT2 found in xinput list; aborting."
  exit 1
fi 

echo "AMT2 is ID '$ID'"

PROP="$(xinput list-props $ID | grep " Finger " | cut -d "(" -f 2 | cut -d ")" -f 1)"

if [ -z "$PROP" ]; then
  echo "No Finger property found in xinput list; aborting."
  exit 2
fi

echo "AMT2 Finger property is ID '$PROP'"

echo "Setting $ID:$PROP to 2, 2, 0"
xinput set-prop "$ID" "$PROP" 2, 2, 0

echo "Setting synclient options"
synclient ClickFinger3=2
synclient HorizTwoFingerScroll=1
synclient TapButton2=0
synclient TapButton1=0

Line 21:
PROP="$(xinput list-props 27 | grep " Finger " | cut -d "(" -f 2 | cut -d ")" -f 1)"
should be
PROP="$(xinput list-props $ID | grep " Finger " | cut -d "(" -f 2 | cut -d ")" -f 1)"

The above script will only work if your touchpad happens be be on ID=27. Once I made that change it worked for me.

Creating a configuration file in /etc/X11/xorg.conf.d instead of this script should make settings persistent across system restarts. See https://askubuntu.com/a/1316185/201097

Thank you for the correction, @briandrawert.