There are so many tools on pc that already address all this (blocking, triggers etc.)

PC could add checkoff boxes saying things like
"want absolutely honest answers" or "please be gentle, I'm in a rough state"

But people learn to better cope by actually interacting with actual people. Everyone has a responsibility. If the mods see someone asking for a diagnosis, they can always post a reminder to the OP.

This nanny state of PC is a little frustrating. The message is that people here can't take it, but I know that this is a community of people who have a lot of strength. People learn by interacting. If they don't, that's what the ignore button is for.