Certainly getting the hang of this now Acorn. It’s been parsing the mobile size considerably. On the pasteboard I’m using arrow indicators where placeholder images are used (for my benefit only). Certainly can be used on the larger variants as well.
My work flow - I bring the image in and size it. Note the size, and export the photo and save. Now delete the photo from the design. Draw a rectangle the size of the photo, in placeholder replace with photo, generate image unchecked.

Very handy tool. I’m still a bit foggy on the thumbnail idea, but the replace photo option is very handy.