Using this extension consumes almost 100% CPU Rated 1 out of 5 stars

I'm unable to use this extension, TB binary starts to consume almost 100%, when starting the classification on a folder, it advises about the Javascript getting hang.
I tried to use it on an IMAP account, with hundreds of folders, and thousand of mails, TB is 3.1.8
A pity, because this is a promising add-on, and it would make that manual sorting task much easier.