[Pacdoc]

Scientific American, Nature and New Scientist have lots of images.
The generated ePub files using the ePub reader do not put images with the articles and some images are huge.
If I convert to awz3 or mobi after download as ePub they read much better

How can I get the Fetch receipes to automatically produce either awz3 or mobi?

I have tried to find the answer dozens of times and wherever I start I draw a blank