Most of the Dev team uses EFLC so if there any issues like one we have at the moment where a callout is inside a building that is only available in EFLC it won't effect you if you get it too.
In other words, if you're using EFLC, things that the developers do that are EFLC specific will work correctly for you. You'll also have access to more police cars (police charger, police bike, police stinger pursuit car) and more character models.
So yeah if it's only to play LCPD:FR, get EFLC and use The Ballad of Gay Tony.
But I advise anyone to get it on Steam because if you ever break your game you can just use steam to repair it rather than totally reinstall it.