Just wondering if the mod allows for thumbnails that are unique and separate to the article itself. That is, not to resize the image within the article, but allow you to have a thumbnail of a different image. Hope this makes sense.
But using RAXO All-mode PRO you can do what you described.
If you want thumbnail in the module block only (whithout this image or thumbnail in the article) do the following:
Add the image to intro text. Module will make the thumbnail.
Now go to Article (Edit) -> Parameters (Advanced) -> Intro Text: Hide. So the image won't appear in the article itself.
So you'll get informational block (e.g. on the front page) with thumbnails, and the article without those thumbnails. At the same time you can have any other images in the body of the article.