I specifically left out the noise reduction on the crop to give a sense of what the camera/lens combo can capture. There are some single-pixel wide details, so the resolving power of the lens+extender is there.

Full EXIF is available from Flickr, but to save you a click: EOS R7 RF100-500mm + 1.4x -- 700mm, F/10.0, 1/400s, ISO 1250.