Certain things would have been easier, like the Sneak attack in "Blood of the Innocents". And I ran out of sexps two-thirds of the way through FREDding "He Who Rides the Tiger", so I had to go over the events with a fine-toothed comb to squeeze every last node I could out of them. (Take a look at all the send-message-list conversations in that mission.)
But ST:R does has a bunch of FSO features; they're just not activated in retail due to judicious version-specific commenting. The custom main halls, custom debriefing personas, cruiser nameplates, ai profile, FS1 music tracks, and FS1 hud are all FSO features.