I tried that, but it got annoying real quick. I also tried watching with subs first and then without, but that’s just boring. And I’ve tried watching with Japanese subs but then I end up reading instead of listening, which defeats the purpose.
Sometimes, yes. And that helps because there’s so much text on screen that I usually don’t properly look at any of them. 
Yes, but it’s sometimes the other way round: I hear the Japanese first, then quickly check my comprehension by deliberately looking at the subtitles. Sometimes I don’t read them at all. And sometimes I wouldn’t understand a thing if they weren’t there. I’m noticing I’m relying on subtitles less and less, so it definitely works, even if more slowly and indirectly than other methods.
Thank you. I know I’m not the majority, and most people will be extremely happy with the way it’s setup now, so I don’t think you need to change anything just for one user (or maybe a few). Ideally I would like to be able to set something to watched, even if it is with English subtitles. To take the book analogy, in my mind watching with subtitles is more like reading with a JP-EN dictionary (always open, admittedly), watching without subtitles more like reading without one. Of course you can’t control how people watch - after all, you can watch a show with subtitles on and never even pay any attention to the Japanese audio at all. But then, you can also read a book by throwing it into DeepL (bad translation, but better than nothing), or having the translation open in parallel. Natively doesn’t check on that, nor should it. It trusts users to log useful, relevant information.
As time goes on and I grow more comfortable with my listening, I think I could even start grading, even with subtitles on. I know there are series where I need them only rarely, and series where I couldn’t do without them: parts with lots of mumbling, lots of dialect, lots of specialized vocabulary. On the basis that everyone is trying their best to grade helpfully, I’d probably allow comparisons between any kind of “watched”, subs on or off. But I just have an ideal situation in my mind and you have actual experience with running the site and seeing the data, so I’ll trust you that this way is best 