"dont upscale" option in "save photos as"

[mw]

This has been suggested before, but I would really like a toggle "dont upscale" to disable upscaling of photos when using "save photos as". I am frequently cropping 60MPixel files and then downscale them to 24MPixel. But if I have to crop to e.g. 12MPixel I do not want an upscaling of these smaller images. Further I would like a scaling option to specify the size of the resulting image in Megapixel i.e. 24 Megapixel. This would save me from calculating the pixel resolution in the box option.
Thank you very much and best regards, Markus

[Kevin M. Cox]

I came looking to request the same thing, but in the Upload dialog.

Having this available in any dialog that re-save the photo would be very helpful.