Depends on what “just” importing things via URL means. You can, if you set up an import map, import by URL from a properly installed node_modules directory. I run my entire test/dev setup for the project with URL imports (using an import-rewriting webserver because import maps weren’t supported yet when I set this up). But I don’t really intend to make it my problem what CDNs do when a package appears multiple times in the dependency tree.