You would normally go by what the company considers to be the “interpretation” of an action, I would think. It is difficult for me to say, because, as far as I am aware, there are pros and cons by going by the “strictest interpretation” of something, and by “what the company considers X to be”. I don’t think this is an easy question to answer. Safest bet, in my opinion, is to just go by what the company considers.
That being said, SE has already adopted a “don’t ask, don’t tell” policy about ACT. The developers are well aware that it is used by the majority of raiders, and just about every world-first/speed-kill group. They watched the Ultimate streams, which had and ACT overlay present usually, and did nothing to the individuals in the streams. They have consistently said, in the past, that so long as ACT is not used to harass other individuals, and as long as people keep it under wraps, they will not do anything about it. Probably because they realize that it would negatively impact the raid scene (e.g., a lot of raiders would stop playing), or that people would just invent a new program with new workarounds (e.g., ACT v2.0). Keep in mind that, when people report ACT harassment, the punishment is usually under the “harassment” portion of the report; rarely is it ever about the program usage itself. The same would be said if people were harassing you with screenshots of your character naked, or with lewd /tells.
It’s my personal opinion that, if SE has not shown any outward concern or any plans to actively punish the usage of third-party tools (this includes ACT, ReShade, Chromatics, and mod usage), then why are other people getting so up in arms over them? If the sheer possibility that someone could be running ACT or a mod of any kind (not just the nude mod) bothers you that much—again, just the possibility of it—maybe you should take a few steps back from the game to clear your head. A program like ACT, or things like clothing or hair mods, are not going to suddenly ruin this game. If this game crashes and burns, I feel certain in my guarantee that it will be because of something far more larger, and probably with the design of the game itself.