First, let me say that the Beta of Publisher looks fantastic. The work is, as always, exemplary.
I would like to add a feature request for support of video. I have a large esoteric pdf that was published and needs an update.I originally used an old version of Adobe Indesign. I've been considering Publisher for the job. However, my book uses many instructional videos. I can't use publisher without video support. This needs to be done by Publisher when the document is exported to a pdf and/or epub formats.
Tree book print media is still viable, but it doesn't have the popularity that it used to have. Now we have so many other ways to create media. Exporting to pdf is very nice. Wouldn't it be even nicer to be able to export to responsive html5 as well? Then, those of us who develop apps could, perhaps develop using Publisher. While you are at it, how about exporting to the Apple store ebook format as well? I know that these feature requests are "asking for the sun, moon and stars", but you are programming geniuses. Maybe you can add some other export options that might give users even more latitude and flexibility.
Thanks for your hard work. I've moved totally to Affinity Designer and love it.