I am not sure there is a "community consensus", but it shouldn't be done. If the same exact answer can be used for multiple questions, then it is most likely that the questions are duplicates.$^*$
If a user is just copying and posting the same exact answer to various questions, and the answers don't really apply to the questions, then this is what flags are for. Raise a custom flag explaining that the answers are exact duplicates by the same user. Flag the questions as duplicates if appropriate.
$^*$I say most likely, because sometimes a user might provide extra information in an answer that was not the focus of the question it was posted on, yet that extra information might serve as a more focused answer for a different question that is related but not a duplicate.
In this fringe case, I would say that instead of just copying and pasting the same answer, it might be better for the user to post a link to the first answer while additionally pointing out the main key points that are most important in the new question in this new answer. It would also be best to supply some additional information/focus that applies more to the new question. That way the new answer is not a duplicate answer, identifies that the question is not exactly a duplicate, and it provides a way for future readers to learn more on the topic by going to a related question/answer.