I haven’t read all comments so I don’t know if anyone made this suggestion already, but for a demo uploader, you could probably just have all the file contents

I haven’t read all comments so I don’t know if anyone made this suggestion already, but for a demo uploader, you could probably just have all the file contents replaced with zeros, or stand-in data of the same content type (eg all videos turn into a video saying thanks for trying it out, padded with zeros to the original upload size)