How does it work with single page apps? If the data is loaded from the server, does it save the page contents as full, or just the source of the page?
I have also updated the local server for fetching from origin missing resources. For example, a webapp may load some JS modules only when you click buttons or links, when that happens and the requested file is not on the zip, it will fetch it from origin and update the zip. So mostly you can back up an SPA by crawling it first and then using it for a bit for fetching the missing resources/modules.