I'm not sure why they dropped this character after "The Search". It makes perfect sense that the Romulans wouldn't trust Starfleet to have a cloaking device unsupervised (especially so soon after the Pegasus incident)
Of the many recurring characters on TNG and DS9, they never really
had a major recurring Romulan character. Sela and Tomalak were in four episodes each (if you count "The Mind's Eye" and "Future Imperfect"). Cretak was only in three and not even played by the same actor.
She was pretty unfriendly to being with, but might she have ended up bonding with the crew?
How would her presence have affected episodes like "Visionary" and "Way of the Warrior"? How would she and Worf (and perhaps eventually Martok) have been around each other?
Of course, Martha Hackett then probably wouldn't have played Seska.
What do you think? Would it have been interesting to keep her around or were they better off just disappearing her like so many sitcom kids?