Sorry if it's a stupid question, but hypothetically, would we be able to engineer rather than find a harmless strain of coronavirus with the spike protein of SARS-CoV-2?

If I understand correctly, antigens identify the virus by its S proteins. Would we be able to use the same methods <a href='https://www.nature.com/articles/nm.3985'>as in this paper</a> to replace the S protein in a harmless cold-like coronavirus with the S protein of SARS-CoV-2, and would then the resulting immunity defend against SARS-CoV-2?