Confirm file replace - Replace larger?

I am using the image conversion tool to convert images in hopes of dropping their sizes. I do that into the second open folder tab. Then when I move the files back to the original folder, I'd like a way for it to only replace the images that are larger, since sometimes, a converted jpeg will actually increase in size. Is there any way to do this?

Not currently, at least without scripting, but it's a good idea for the replace dialog options.