Rated 5 out of 5 stars

What a great extension!
I hope the version compatible with thunderbird v.115 is coming soon.

This user has a previous review of this add-on.

About version 115 support.
After some research and trial and error, we decided to take a different approach and create a different extension.
https://addons.thunderbird.net/en-US/thunderbird/addon/filtered-folder-to-favorite/
The results of executing the filter have been changed to display in "Favorites".
As a result, the unstable operation has been resolved.
For those who used this extension and "Favorites" together, it may have been difficult to use.