Problem: Collaborations such as the historical WikiProject collaborations of the week are a proven effective wiki-based tool for improving vital articles, but they are hard to maintain in the long-term, requiring a dedicated volunteer to manage them every week or month.
Proposed solution: Universalize the automation system established for Articles for improvement on enwiki, so that it can apply to any language, WikiProject or arbitrary list of articles.
Who would benefit:
WikiProjects on Wikipedias in any language, and likely other sister projects as well.