Last month I submitted a patch to allow users to drag and drop folders to reorder them in the folder pane of Thunderbird 121.
It worked fine.
However, the Betterbird (a fork of Thunderbird) folks pointed out that there were performance issues with a huge number of folders. And then they added their own code to cache the new folder properties and made it available to us.
I tested it. And found another problem with their countermeasure. Upon investigation, it was due to a bug (technical debt) in Thunderbird's folder caching functionality.
The Betterbird folks have done a (band-aid) workaround for this problem, and have backported my patch to Betterbird 115 and released it (I have not confirmed this, but it appears so).
Meanwhile, the Thunderbird team is planning to fix the problem fundamentally. So my patch will be merged into mainstream Thunderbird after the problem is fixed.
So Thunderbird users will have to wait a few more weeks.
