A couple hours ago, I tried my hand at making Mastodon users shit brix in the "Mastodon's quote-post development is being sponsored" thread by telling them that the same quote-posts they don't want on Mastodon are readily available already now all over the Fediverse except for Mastodon.
That just about everyone in the Fediverse outside of Mastodon can quote-post everything on Mastodon right now.
And that no non-standard, proprietary opt-in or opt-out on Mastodon can stop them from quote-posting Mastodon toots.
Either most of those whom I've replied to haven't noticed yet, or they've blocked me on the spot for posting stuff that scares them. Including that the Fediverse is not only Mastodon.