Blazor REPL import all static assets - both from packages and CDNs as normal JS files. The tool should know which files are modules and which are not.
Example:
The BlazorSize package is not working in the REPL: https://blazorrepl.telerik.com/mmYdEHFR31t74oWj55
Resizing the browser doesn't update my label and I don't see any errors in the UI, but I do see this in F12...