Problem: Often times, related articles (e.g. for various general elections in the same country) will re-use certain conventions, etc. (e.g. whether to treat a coalition as a single party or multiple parties). It is good to keep those conventions consistent among related pages. However, because it each article has its own talk page, it can be difficult to ensure editors of every page are alerted and able to participate in the discussion; this can result in the inability to gain consensus, or else create a false consensus.
Proposed solution: Create a feature which allows multiple articles to share a talk page section. When someone edits/updates the shared talk page section in one of the articles, the corresponding section of the talk page would update for all other articles contained the shared section of the talk page. (Perhaps having a shared talk page section would involve using a common category. Or perhaps it would use a tag hidden from people who read but do not write Wikipedia.)
Who would benefit: Editors would be the ones to directly benefit
More comments: Here is a real-life example of where I believe this would be beneficial. The infoboxes of articles on Australian elections treat the Liberal Party and the National Party as a single political party. I believe this should be changed so the infoboxes reflect that they are two different parties. Normally, I might propose on the talk page of "2019 Australian federal election" article to make this change. However, people who edit related articles (e.g. "2016 Australian federal election" and "2013 Australian federal election") are unlikely to see my proposal. (It would not be practical to post my proposal on the talk page of every article on an Australian election, and doing so could lead to branched debates/consensuses.)