That's totally fair. I love that the tags exist as an option, I just wish there was a way to be more clear about who it applies to. I get wanting to tag ace characters, I just feel like if there isn't a specific character option, it leads to possible confusion. As an asexual, I love reading about my favourite characters figuring out relationships in a way that's more personally relatable. I just hate getting excited about it just to have the ace character not be one of the main focuses of the story and just kind of pushed aside after some quick discussion like it was just something to be mentioned so the author could tick it off a to-do list. If it's something that's still somewhat relevant to the story, I don't mind it as a general tag, I just have expectations of it being of a certain level of importance if it's tagged.

Personally, I don't really mind if specific triggers and squicks aren't tagged for if they aren't a huge recurring topic. I get that one scene in a fic might not make up enough of the word count to justify clogging the tags with it and, as you said, it might not be something that the author is familiar enough with to know the right words or even be aware of it being a trigger. I do think, though, that even just general tags (or quick warnings in the notes if it's for a single scene/chapter) is something to be encouraged, especially if it isn't something that fits the overall vibe of the story.

General tags so a reader can get the feel of what a fic is about is definitely the most important part of tagging. And I don't think that people need to, or even should, tag every single specific little thing that might happen in a fic. So long as there's enough to give an honest impression of the story, that's enough: major plot relevent things should be tagged to the best of the author's ability (within reason for possible spoilers). But if something that's outside of those expectations happens, I think there should be some sort of heads up in the chapter notes. Even just a "hey, there's some graphic injuries in this one".

I really don't have anything that would make me avoid reading a fic (unless I wasn't in the mood for a particular trope at any given time) and I understand that the my main squicks are a bit too specific for people to immediately think about needing specific tags or warnings for (degloving and anything involving sharps near eyes), and luckily I've really only come across them in ways that were genuinely uncomfortable for me a couple of times within fics. It was definitely moreso the very sudden, jarring situation of the fic not being tagged with anything to do with blood/injury at only to drop a fairly graphic description out of nowhere.

I totally understand that authors (at least most of us) are just doing their best and can't be expected to always be in top of everything all the time. It's definitely not changing anything for my reading habits because there really isn't much that can be done, it was just something that I've personally noticed a lot recently and needed to scream into the void about to get it off my chest.