Use-case: I have a draft article (namespace 118) -- e.g., https://en.wikipedia.org/wiki/Draft:Armor_Wars_(film) -- and I'd like to find similar articles within the main namespace (namespace 0) via morelike functionality. Right now, I can find articles that are also in the draft namespace (example) but evidently main and draft namespace articles are kept in separate indices so there's no way to achieve my goal right now.

Motivation: one of the core ways in which experienced editors find guidance for what sorts of edits to make or how to structure an article is by looking at similar examples -- e.g., if you're editing the article about a park in NYC, it can be helpful to look at the article for Central Park as a good example of what sorts of sections, infoboxes, categories, etc. to add. I was able to create a simple tool based on morelike search for this but it only works for existing articles and not for drafts. It'd be great though if after an initial draft was published, there were ways to quickly generate recommendations for what sorts of entities could be added to it to improve the article's chances of success (and give nice follow-up actions for newer editors).

Also, gratitude to @dcausse and @EBernhardson for helping me debug this case and nudging to file the ticket.