@silverpill so I'm not missing anything, just people wanting to overcomplicate things. Sigh.
Consent is not a thing that should be encouraged through non server-side enfored mechanisms because (as we can see plenty today) bad faith actors care not about such things.
Therefore a flag on an actor/object is useless because it requires that crawlers obey it, and again, they can not be trusted to do that.
In my opinion offering this as a solution to end-users is just snake oil.