Huh? The episode is clear on there being nothing or nobody at Trivas. The baddies pulled out; they are not around, and the heroes bet their lives on that. Yet when the heroes get into trouble, they wish to signal for help all the way from DS9, not from potential neutrals or friendlies at Trivas, even though their problem is one of insufficient signal range.
Terok Nor was on orbit around Bajor in order to achieve its mission, as easily visually confirmed. Empok Nor orbits no planet, as equally easily visually confirmed. So our two options are two different missions (which is highly problematic because O'Brien bets everything on Empok being absolutely identical to Terok in engineering detail, without having known intel on the place specifically), or two cases of a station of this type moving across space (and we know one such case worked fine despite the best attempts of the Cardassians to sabotage it, whereas here the Cardassians would be in control).
Timo Saloniemi
Cardassia is supposedly resource-poor. It isn't beyond the realms of possibility that they make their core systems standardized to facilitate interchangeability. We've had talk of "Galor-Class Phaser Banks" which doesn't really make sense if such are only ever fitted to Galor-Class starships, for example.