If the first response is someone pointing out that this post is part of a pattern of repetitive questions from the same person, most people will decide not to respond. If the questioner is too annoying, their posts start getting considered. So far that combination seems to have been enough.

Any healthy community always has some feedback mechanisms to encourage people to stay within an accepted range of behaviour. That is necessary because being generous to everyone is ultimately destructive of the community.

Eventually we will have some questioners who go ballistic. We will also have some answerers who do their best to answer questions despite their being considered. But we can cross that bridge when we come to it.