The hack referenced above, also adds an easier search tool for admin to find cross-listed courses so they can be de-cross-listed. That's awesome too but likely a second feature request. It makes it possible to change the name of the course which we couldn't support so I would like this to just be about improving the cross-listing process.
In addition to the process change, it should have a warning about grades not moving with cross-listed courses and another mention of that when clicking "Yes, I really want to do this" as mentioned in this feature request. Also a link to the generic help doc explaining what cross-listing is.
I'm not looking to make a kitchen-sink feature request, just a cross-list tool that happens to make more sense to the end-user, and satisfy several feature requests and dev hacks over the years.