Ahem. Supposedly, warp fields within the wormhole are a Very Bad Idea. Furthermore, everybody seems to understand this much from the get-go.
But in "Homefront", our heroes speculate that the mysterious opening and closing of the wormhole is due to a cloaked ship going through, and nobody points out "But when we tried that with the Defiant
, we blew the starboard and
the port power coupling!". There doesn't appear to be anything explicit that would make the combination dangerous or otherwise undesirable, not according to our heroes.
We can speculate that the wormhole in the general case doesn't open unless it sees a ship attempting to enter, though. And what would be the point of flying through cloaked, when the sight of the wormhole opening will alert everybody to your transit anyway?
Of course, clever villains might send in one visible ship and follow with an invisible armada - but not too big an armada, because the wormhole will close after the visible ship enters, and getting caught in the closing orifice might ruin your day. But perhaps some cloaked Dominion ships got through in the wake of runabouts or the like, explaining e.g. the mysterious disappearance of Eris the Vorta (initially chalked up as a suicide, but we know the Vorta aren't that selfless!) as a beam-out into a cloaked support vessel...