<p>IMO in your situation I would just add the response into your current answer. While I don't disagree with the answers to the <a href="https://stats.meta.stackexchange.com/questions/1151/what-to-do-when-the-original-question-is-transformed-considerably-after-getting">linked question Macro provided</a> in the comment to this meta question, I don't think the discussion has diverged enough from the original topic to justifying splitting the question/answer(s) across two different threads.</p>

<p>I will say "what is diverged enough" to justify splitting into a separate question is quite vague, but it happens infrequently enough I don't see much reason in trying to layout bureaucratic norms for when it should happen. So the interested parties should just use their discretion to determine if such a threshold has been met.</p>
