I've seen other wikis do exactly that with [series title] manga 01, or [series title] light volume 01. That's why I thought of suggesting it. Unfortunately these titles are going to be wordy regardless as you said because the title of this series is already long on its own, but I think it is more beneficial to have the series title in it simply for the search results.
People that are going to look up anything on the HTR novels are likely to type HTR light novel 3, or Hakata Tonkotsu Ramens light novel 2. More likely the later as that is the series' full name. Just by having them kept as light novel 1, light novel 2 is not going to get the wiki as much traffic as that could be anything. That's putting too much faith in the search engines to look in the URL of the site and the page for those keywords. When the title is not used as much that just puts the pages lower in the search results.
From my work experience in this field of trying to earn clicks, I know many search engines will list pages higher for dropping the names in the titles as well as all other fields (meta, image names, URLs, and organic feeds); I have to do a similar process in my real job.
I can look around and see what other wikis have done in situations like this, but as it is now we are shooting ourselves in the foot in terms of clicks and pages being found, let alone organization.
