[slowsmile]

@JSWolf...I'm afraid that I'm not at all experienced at writing plugins for Calibre -- never done it, though I do frequently use that app. And if I did write a cleanup plugin for Calibre it would probably take me a while to learn the Calibre way of doing things(ie the libraries). I'm currently learning PyQT5(for use with Sigil plugins), which seems much easier to use and far less cranky than Tkinter. I believe that the Calibre plugins have been using Qt for a while now. So I am interested.

But for now, I'm not saying yes or no to your request. I'll look into it first and then let you know later on this forum if I can do an equivalent cleanup plugin for Calibre. Hope this is OK.

Also, just a reminder -- my Sigil plugin can cleanup both epubs and imported html docs. So what you could perhaps do is simply convert your doc to epub with Calibre, then just open your epub in Sigil and run my CustomCleanerPlus plugin. Doing this will cleanup and remove any dross html data that isn't needed in the epub html, cleanup your stylesheets and will also change or remove html data to ensure compliance with epub 2 (this helps to reduce Epubcheck validation errors later).