This morning I tried to delete the Custom URL from the Host page for one Webflow hosted site and enter it into the custom URL for another Webflow hosted site. A couple of hours have passed and I am getting a 404 error. Do I just need to wait for Domains.google.com to update my DNS or am I doing something wrong.
Fixed it. You just need to move the URL, then publish your site. That was easy. I just hadn't published it yet.
P.S. The reason why I did it that way is because the old site was really just a placeholder and didn't have any real link juice yet. I didn't need to forward the site, just replace.