Click on the extension icon in the navigation bar of the browser and it will download the .aax files for every episode on the current page.
If a podcast has multiple pages you will need to change the page and click the extension icon again, after the last file of the current page got downloaded. (You can increase the number of episodes per page)
Navigating to a different page in the tab or refreshing will cancel the download.
NOTE: This does not circumvent any DRM protections. You get the same encrypted .aax files, as if you clicked every download button manually.