Maybe this should be a separate suggestion, but it's in the "source refinement" theme - I'd like to see the possibility of adding a top level domain to ensure you're getting results from an area with specific information pertinent to your query. If I'm asking about taxes, but only interested in EU taxes, I'd like to exclude irs.gov or include EU or country tax orgs. Or if I'm looking for federal program info, I can ensure the USDA.gov is a primary source rather than have to adjust the prompt over and over to get results from there.

Would love Google scholar search!