Thing is, the way it is right now you might as well blacklist everything because ever game has every tag under the sun. Why else do you think that every time a game is posted the first thing that happens is a million questions about how much of a tag is actually in it?
Ultimately though I think you have an overinflated idea of what I mean when I say significant. Basically, it boils down to this. Is the tag something that the game actually contains in any meaningful way, or is it just a throwaway scene somewhere in the middle.
For example, Friday the 13th is not a porn series just because it has some teenagers that are about to get fucking when Jason shows up to spoil their fun with a machete. And conversely a game with a single footjob is not femdom, a game with a single kiss is not romance and a game that contains a poster of a slasher movie on the wall in one scene is not graphic violence.
And you are not doing anyone a favor by making them blacklist them all because the tags told them that this is what they were. All you are doing is making the tags meaningless.
At this point I think you'll realize that I am not exactly setting a hugely high bar to clear. Nor am I unaware of the fact that some tags (hint: NTR) are more sensitive than others. But all I am advocating for is a tiny bit of common sense. Just enough to make a tag actually mean something.
The problem with your examples is that people don't care if there is one scene of scat or the entire game is based around scat. If they don't like it and prefer to avoid it, they want to know about it right away. Same with NTR. People don't ask "how meaningful is it?", they ask "can you avoid it?" which is not the same.
Of course I understand that it's not the same a game in which you have to agree to NTR to actually see over half of the game scenes (which might not be NTR) than a game in which you're only cucked at the very beginning as a plot point. However people want to know about these.
If you arbitrarily decide that you don't need a scat tag because it only happens once if you choose the "peek" action in a certain point, then you will make players angry if they unknowingly choose that option. Unless you're suggesting the posts also include a "Scat warning: don't choose to peek", "NTR warning: you can refuse to let the heroine meet other people", "Gore warning: At one point in the game, a minor character will appear mutilated, this can't be avoided."
And so on, and on. Meaning people will not only have to filter through tags, but also take extra steps to ensure the game is not offensive to them.
