If you are just looking to include it client side from CDN is probably the preferred method. Because otherwise I think you have to rewrite the URL anyway since a relative url won't work to my knowledge. You have to find the file record and get it's Netsuite url and replace it in the rendered page. If I am understanding what your trying to do.
I had to do this for an app with built css, js and image assets, most resources I could inline using webpack, but there were still some assets that needed rewritten. I just put a check in the code if there were relative assets in the page template and then would replace all instances and save the file back so search and replace didn't have to happen for every page load. This slows down the load time of the first time the app loads after a new deployment and then all subsequent ones are quicker. Not my favorite way to do things but it seems to have worked reliably.