What if I want what I publish to be known only by word of mouth?
What if I consider (some or any of) my ideas to be un-indexable, not directly suitable to representation in any hierarchy other than those I may set them in?
Yes, sorry, it was a rhetorical question in response to previous.
Taking either step you suggest (along with robots.txt or eqiv.), it would seem fair to expect that Brave, Bing, whomever, would not feel it their neutral/natural domain to include in a public index.