What are grounds to propose a subjective trope or audience reaction?

I know that both of them are "discouraged" from being launched, but I have something in mind that I think has become rather prevalent these days. How do I know it's safe to propose?

Simply put; Is it a complaining trope? Is it common enough to note(to say the least, this factor will come in as people give suggestions)?

Those are the two key points to look at.

The first rule of proposing a new audience reaction is: don't. The second rule is: see the first rule. If you really think you've found some new way for people to react to media, run it by us here first. You're probably wrong.

For subjective tropes, it's a little less clear-cut. It is certainly possible that more distinctions could be found among them that we haven't picked out yet, but extreme caution should be exercised. It's far better to propose a trope that is pointed out to be subjective during the TLP process than it is to propose one that you know will be subjective out of the gate.

Run it by you "here"? As in I can tell you what it is right here in Wiki Talk?

Well, you could use Wiki Talk if you want. No reason not to.

I'm not 100% informed about the subject, but from what I've read and seen in TV Tropes, I'm gonna give my honest opinion.

Every trope, be it audience reaction or subjective or whatever, should get the right to be proposed at TLP. Even YMMV are not bad, and in fact are one of my favorite subpages for all the fun there. Sure, a subjective trope/audience reaction might attract complaining, edit wars or flame wars, but if that's the case, fellow tropers will just tell their bad omen at TLP, and discard it if need be. I see no reason to tell a person not even try to share their idea.

Look, share away. I have no control over people's ability to create whatever they want in TLP. But certain types of ideas should go straight to the discard bin.

The YMMV division covers a very specific scale of ideas. Subjective tropes (only reason not objective tropes is being too easily reinterpreted like Moral Event Horizon), critical observation (describing the audience reactions like Hype Backlash) and quality declarations (judgement calls on the work itself like Idiot Plot).

Proposing a "Quality Declaration" trope is about the hardest thing to do now, the tv trope community looks down on that. If you can find a legitimate subjective trope and critical observation that the wiki is missing, feel free to try.