Is it common practice to have a separate "Further Discussion" after the conclusion in an academic article? I received reviews of my manuscript for IEEE Transactions.

One question from a reviewer, about a common misconception regarding the technology, is interesting but is not relevant anywhere else in the paper. So, my supervisor suggested that I add a new section after the conclusions titled "Further Discussion."

I was just wondering if it is common practice to have such a section.
Virtually all papers I've seen end with the conclusions section (otherwise, it wouldn't be the conclusions!).

The best way to incorporate such changes would be to include it at the end of the current discussion section. Perhaps you can subtitle it "A brief note on X," where X is the topic of the comment. Alternatively, you could include it as an appendix if it requires a more extensive and extended discussion.