Oh, I see – sorry.
There is no such option out of the box but you can do this using a trick based on WordPress image sizes feature.
As you know watermark (using our plugin) can be applied to specific image sizes. Let’s say user uploaded images generate 2 image sizes: one small for thumbnails (800x600px) and the second, larger for anything else (3000x2000px). If you are watermarking them, there is no option to download it without watermark applied. But if you created another 2 image sizes (in your theme) of exact same sizes, but named differently (for e.g. with a suffix _download) you could disable watermarking of it and use as images-to-download only. You could do otherwise too and prefix the images with watermark applied.
This way you’d have 2 sets of images of exact image sizes, with and without watermark applied.
It requires a test, but I’m pretty sure it will work as you’d like to.
