A script to set the homepages for both Safari and Chrome. From https://www.jamf.com/jamf-nation/discussions/21386/change-current-users-homepage-and-startup-pages-in-safari-and-chrome

SetChromeSafariHomepage.sh

#!/bin/sh

# SetHomepages.sh
#  Change Chrome and Safari Homepage

# This script assumes that default preference files for all three browsers have been installed
# with FUT/FEU options in Casper.

# Define homepage

homepage='https://www.yourhomepage.com'

# Stop all open browsers so settings are not over written by Coogle Chrome's open session (it re-writes every 1 min from memory)

sudo killall -z -m "Google Chrome"
Sudo killall -z -m "Safari" -signal

# Loop through each user to set homepage prefs
for user in $(ls /Users | grep -v Shared | grep -v npsparcc | grep -v ".localized"); do

### Safari ###

# Use defaults command to set Safari homepage
su - "$user" -c "defaults write com.apple.Safari HomePage $homepage"
su - "$user" -c "defaults write com.apple.Safari NewWindowBehavior -int 0"
su - "$user" -c "defaults write com.apple.Safari NewTabBehavior -int 0"
su - "users" -c "defaults read com.apple.Safari"
echo "Set new Safari homepage to $homepage for $user."


### Chrome ###

# Define Chrome Preference variable
chromePrefs="/Users/$user/Library/Application Support/Google/Chrome/Default/Preferences"

#Parse the Preferences json file to set the homepage
sed -i '' 's|"startup_urls":"[A-F0-9]*"|"startup_urls":""|' $chromePrefs
sed -i '' 's|"startup_urls":[[]"http[^"]*"[]]|"startup_urls":["$homepage"]|' $chromePrefs
sed -i '' 's|"homepage":"http[^"]*"|"homepage":"$homepage"|' $chromePrefs


done

# Set homepages in user template for future users

# Safari
cp "/Users/$adminUser/Library/Preferences/com.apple.Safari.plist" "/System/Library/User Template/English.lproj/Library/Preferences/com.apple.Safari.plist"

# Chrome
cp "/Users/$adminUser/Library/Application Support/Google/Chrome/Default/Preferences" "/System/Library/User Template/English.lproj/Library/Application Support/Google/Chrome/Default/Preferences"

This is awesome. I've been searching everywhere but do you happen to have one for the new Microsoft Edge Chromium? I'm looking where to set it either via bash or plist and cannot find anything.