Image handling confusing

I guess I expected more; the logical thing for an affiliate product display plugin would be close enough integration with cj.com and other major affiliate programs to suck up appropriate images for each product, but that doesn’t happen and no useful images are displayed, only a generic placeholder shows. The Instructions page obliquely hints that product images might appear if the ‘regenerate thumbnails’ plugin is downloaded and run ‘after installing this plugin’, but no, that doesn’t do it either, although when that plugin does run it’s behavior suggests it’s resizing every damn image in my Media Library, but thankfully it doesn’t do that after all (where the new resized images go remains a mystery, but at least it’s not destructive). FINALLY by perusing this Support forum I discover that image handling is all supposed to be done manually and there can be copyright issues yada yada to add to the question of ‘why wouldn’t I just use the provided code from cj.com that already has images associated with them?’.

Eventually I arrive at the tentative conclusion that this plugin is simply for displaying linked images with manually entered text and automatically generated buttons below them, with the plugin’s primary function being to display these image-text-button combinations by a selectable pattern of columns and rows. Wouldn’t it have been great to have been told that up front I say to myself, instead of having to go through a protracted Sherlock Holmes mystery process of figuring it out the hard way?

Oh well I’ve got it at least partially figured out now, and I’m thinking this plugin might have some limited utility eventually, but there are still some questions remaining so I’m asking them here.

1) If I understand correctly, the Gutenberg and shortcode options are intended to be two different ways of accomplishing the same thing. Except they don’t. The ‘Link to the page I need help with’ at[ redundant link removed ] is done with the Gutenberg method and a second page /test-page-2/ is done with a shortcode, and the image sizes are different. Is this supposed to be a feature, or is it a bug? Is there any particular reason to use one or the other, like in terms of page rendering time or SEO or just having the images displayed in different sizes, or what?

2) What is the full and real story about the Regenerate Thumbnails plugin please? Spare me another hour or two of detective work if you don’t mind. Why, when it indicates it’s resizing every image in my Media Library, does it not appear to do anything? Are there new thumbnails created somewhere in some secret place? How am I supposed to access those secret thumbnails when I add or edit a Product? OR am I supposed to just select any sized image I’ve uploaded to go with my product and THEN click on the ‘Regenerate Thumbnails’ button, and whatever secret place the thumbnails are stored in then gets accessed by your plugin and I never have to bother my pretty little head about them again?

Thanks for your help.

The page I need help with: [log in to see the link]