For me, warning in blurbs are enough. I thought you want to delete the blurbs, I'm sorry But it comes to a cost when only some of your chapters tagged mature and others are not. I agree with @DasIstWunderblyat to put the summary in description of such chapters, and description still appears even when I scroll the chapter down and not seeing the entire chapter itself (I mainly uses desktop version). I agree that putting disclaimers... well, interrupt the reading flow.
Yes, the game was a shock for her. But now as I am adult, she watched serious genre of movies within that range, and she is actually fine with it (she has been always a horror/thriller fan) so I actually get confused 🤣 maybe she was holding back when I was under 18.
Mental health: No, no, don't sorry. Sometimes I need the reminder as well. Those traumas can relapse (cmiiw). It is the same here, younger generation are more accepting about the issue, and somehow the older keep saying that the younger ones are having strawberry mentality (I wonder if this term is widely used?)
Imo, most people prefer the middle. For me, depends on the scene. I can be both extreme but really, in the end, it's about the scene. Sadistic murder with very much sugarcoating? Idk if I want to read that, unless you really can tweak it out without altering the meaning and depth that want to be conveyed.
Well if you put a warning, when the reader clicked proceed to read, it is assumed they read and understand the warnings. That's basically me but I haven't ever write something that needs the blurb, so... maybe others can elaborate more for this.