Steps:

• Change to proton-experimental
• Run the game once to generate the prefix (it will crash)
• If running ProtonTricks as a flatpak, use FlatSeal to grant it permission to entire filesystem
• Use ProtonTricks to launch All-In-One Patch
• Extract mod Expanding Fronts to STAR WARS - Galactic Battlegrounds Saga directory
• Use ProtonTricks to Run a commandline shell and then execute the command winetricks directplay and then exit to fix LAN multiplayer
• It may also be necessary to disable firewalld for multiplayer
• Rename or delete player.exe from the Game directory
• Copy and Rename battlegrounds_x2.exe to player.exe
• Run the game from Steam
• Be sure to run the Configurator and set your resolution and check the boxes to remember your choices