Yes, those technologies would fall under the treaty. We don't know the text of the actual article so this is a little awkward to debate, but it is said repeatedly that the treaty bans cloaking devices.
You cannot argue that your examples have nothing to do with cloaking when they cloak the ship that fields them.
I absolutely can argue that they having nothing to do with cloaking when their primary purpose is other. That is precisely what I argue, and I not only argue it, I assert it.
I don't believe for one second Starfleet/The Federation would suppress those techs just because a side effect of the tech is to cause invisibility to sensors. An advanced warp drive that, say, allowed them to travel at warp 10 and higher, safely? New materials that, say, resulted in a 10-fold reduction in cancer among ship crews because of reduced radiation/particle exposure? And they'd abandon those things just because of this treaty? Not a chance. And neither should they have abandoned phasing.
This is exactly the kind of factual and legal nuance that needs to be considered before casually assuming a technology is subject to this treaty. This overbroad interpretation of applying it to techs that have even a secondary effect of cloaking gives the Romulans an automatic veto over the Feds creating any new NON-cloaking tech that by accident creates a cloaking effect. The Treaty was
not created for that purpose and both Federation jurists and legislators would likely and appropriately reject this interpretation. When considering what to do in odd situations under the law, it is not at all strange for jurists to consider the
purpose of a statute or, in this case, a treaty.
You're right: you can argue and assert anything you want. That does not mean it makes sense. A technology that does more than one thing, and one of those things is cloaking, can not, by definition, have nothing to do with cloaking.
You are changing topics a bit here.
Undoubtedly, the treaty can have unexpected consequences; laws often do. There are differences between law and technology in our time. You are touching on the question of whether the Federation would abide by the treaty. That is a different question.
Maybe you are right, that the benefits would so outweigh the consequences that the Federation would violate the treaty. The legal thing to do would be to renegotiate the treaty, not simply violate it. I agree with you that the provision gives a significan upper hand to the Romulans. But, again, that is a matter for renegotiation.
But that is hypothetical, and everyone in the show, including Pressman, concedes that the phasing cloak (it even has "cloak" in the name) violated the treaty.