Yeah, it makes sense Firefox has caught up to Chrome in that regard. It was always a bit unsafe that they allowed local access by default, and it was dumb of me to rely on local access for things to work. Feel free to write what worked for you here in the comments, although my official suggestion to people would be to set up a local server (using whatever method you prefer/find on Google for your OS) and run it from there so there's no way of accidentally leaving the local file access open after you're done with this.