If twitter had ever had a posting interface like this I would have actually liked twitter. (Seriously I used to complain all the time that this ought to be possible on twitter and it never was. You could restrict who replied, but you couldn't disable quote tweets, which were usually worse.)

Someone quote tweeted me and then blocked me from replying while letting everyone else reply. That's some really cowardly behavior.

How do I find this in Settings? I don't see it.

Folks here are really trying

Oh wow, that's really good. I like this! A lot!