Currently, I use url:imgur to search for posts that have images, which gets most but not all of them. (It really only works because the default image format is a linked image.) This can't possibly work after the migration, so it would be nice to have an alternative built into search that returns everything containing <image<img, and maybe also the opposite, something that finds posts without any images.
I guess this might count as a "wholly new site feature" and be out of scope but I'm asking anyway.