robinodds forget about merge.. its core level issue .. some numbering issue. MOVE is the only easy solution .
why you want to merge discussions ? moving is the easy solution .. no need to worry about discussions numbering and errors .
usually we want to merge when its duplicate to something right ? if we merge we will also lose post url again google will punish if we deindex pages (merging)
if we set at forum level approve each and every post & discussion we can just play with MOVE feature .. this is easy and makes life simple .
even flarum.org has around 30k discussions and they can not merge in some cases .. IDK why they did not given importance to move feature ... maybe they consider based on the download count of the extension to spend time on it.
i wish i was a developer to make our dreams possible π (praying god)