For now, unfortunatelly, i no see chance for make that.
Problem with Base defense is in quest terms - quest appear only if player is in party, if is leader of this party and if have in main inventory cryptex. I think so this terms is controlled by core program.
It would be necessary make completelly new quest for travel portal appearing, but key files in gamedata is unopenable in Reanimator.
...and honestly, who would want to fix a game for which other people take money ?