I doubt the Romulans would make the kind of distinction you're making. The end result is that the ship is
cloaked. Hence whatever technology is leading the ship to be cloaked is a de facto
And I don't see how phasing technology isn't, if not a weapon, at least a system with obvious potential for weaponization. You're making whatever's phased invulnerable to weapons. Unless the phasing technology somehow didn't also act as a cloaking technology, you've just created a technology that could be used in an obvious first-strike attack.
Hell, it's Genesis all over again, where I respect the scientists' noble intentions but the potential for trouble is obvious.