reverse default pop (suppress) on large images

[Cone-head]

Example: just loaded a page where the first, header, image was 1024x768. I don't want that popping up larger except maybe by my action-request. Looking at the Options of the extension there seem to be ways (somewhat obscure to me) to suppress the pop-up. But, what I'd like is a setting in Options to reverse the default - based on the image size, i.e. DON"T enlarge IF x-size or larger UNLESS user keys CTRL with mouse-over. The x-size picker could be any of the various size selectors one sees around the web. Maybe a slider would be best.