I just kinda wanna jump back in here super quick and address a couple of the points you've made. When I'm talking about consent in this situation I'm primarily imagining a situation where two adults are consenting to not only the type of activity they're involved in but the use of their character's image(s) in content being made publicly available online somewhere. I know you and I were talking about the shotgun-nature of mods but since I seem to be the one who dragged the word "consent" into the thread I wanted to clarify where I'm coming from when I say it.
To this point, when I'm making an argument against stepping in, it's primarily because it doesn't make a whole lot of sense from a development perspective. As I said earlier in the thread you can just take a look at XIV's competitors to see that the battle is one you can't win without hurting a large population of your players so developers tend to pick and choose which fights to take, and that generally boils down to "are these people using this to gain a competitive advantage?" and if the answer is no then they're generally left alone. I'd love to talk in more detail as to what those steps they'd need to take actually are but I really don't think Square-Enix would appreciate me talking about how the sausage is made, so to speak, so I'm going to leave a lot of that out of the thread. It's not that you can't lock down something like this, only that doing so would be prohibitive to where their production pipeline would slow quite a bit while doing so and it's a lot of resources to spend on something other than content creation or actual anti-cheat and dealing with botters and hackers.
They could potentially scan files and processes like Blizzard's Warden does, but not only does Warden not seem to care about these kinds of mods anyway, you also open up people who use ACT or Reshade to potential scrutiny in the process. Those are easy exceptions to make, but I'm just trying to illustrate that there's more to it than them going "Let's ban those mods" and they're gone in a week as a result. Blizzard also used to include a watermark in your screenshots that could be revealed with the right tools, and that watermark contained the screenshot taker's internal Account ID (not something you could login with), as well as other non-personally identifying information. I'm not sure if they still do that, but that's one way to target players using mod content maliciously as well. This is easily circumvented by more tech-savvy users however and, between metadata and something like Warden, would also opens up another can of worms about right to anonymity and other issues and then suddenly we're talking about "Don't be evil" and backdoors and w/e else and it gets messy.
Anyway, I think the argument you're making is totally fine and makes complete sense, and there are certainly some people who are going to be more interested in being dismissive of this kind of thing than wanting to really talk about it, but whichever way you follow anyone's logic you quickly wind up in that grey area you're touching on which is why I'm trying to stay out of the moral issue and focus purely on the technical one when discussing my reasons against it.
Ultimately the point I'm making is that enforcement is nice to think about but everything requires resources. You have to develop software to do what you need and that means paying people to do it and maintain it (because it'll definitely be circumvented), and then paying people to sift through the data and paying people to action those accounts. Beyond that, you have the PR battle. You see a lot of players in this thread talking about how they would feel punished by such actions, and whether or not you feel that's a legitimate moral argument to make, it's still a practical one for the developers and the company to involve themselves with and risk alienating players through word of mouth. Any kind of large scale change to target this kind of thing is going to be picked up by the community and games press, and all it takes is one person making the inevitable comment "They're spending all this time on this when there's still botters and hackers and issues with content generation?" to ignite a PR firestorm, which will result in more articles and angry threads and etc, etc. "They're enforcing this part of the ToS but they aren't enforcing the part about parsers. Someone yelled at me about my DPS, it's hypocritical to do this one thing and not this other thing!" It's something than can spin out of control pretty fast, which is why a lot of companies don't voluntarily step into that snake-infested pit because not much good comes from it.
If Square-Enix decides the bad PR from the mods is more costly than leaving the mods alone though then they can try to wage that war as their peers have and I'd be curious to see how it goes should they decide to.
Sorry for the walls of text. I've always found this stuff super interesting and could talk about it all day, and you've been making respectful replies so I wanted to do so in-kind.
Edit: To add even more text! I'm sorry. As usual, take everything I'm saying with a grain of salt because I'm not an expert and I'm not involved in the processes I'm discussing here.