@Kagamimocchi I'm actually the typesetter, not the translator, but I can answer your question. Basically it's not actually there in the RAWs and I think I've only bothered to add it for 1-2 volumes but I forget the rest of the time, so that's why lol. If you really want to know which chapter it goes after, you can look at the table of contents and each extra page generally goes after each of the chapters. So for example, Kanao's name goes after 161, Kotoha and Douma go after 163, etc.
Normally they're separated by chapters in the actual volume release, but since we release magazine chapters separately, we just release all the volume extras together instead.