Good news: My Spoonflower swatches were delivered over the weekend!
Bad news: I may have made some slight errors when sizing my images for upload, causing them to be printed just a tiny bit bigger than I’d intended.
But there is some more good news… as far as I can tell, all of the colors seemed to print true to their respective source images. So after I resize and re-upload my designs, I should be ready to order a new set of swatches without making any further adjustments. More on this when the resized swatches arrive!