Change the default Dock stack content display style
This would change the style of all stacks to list, but you have to relaunch Dock to apply the changes:

for n in {0..19}; do /usr/libexec/PlistBuddy -c "Set persistent-others:$n:tile-data:showas 3" ~/Library/Preferences/com.apple.Dock.plist; done 2&gt; /dev/null

You could run it every 8 hours by running EDITOR=nano crontab -e and adding a line like 0 */8 * * * for n in ....