I'm working on revamping the CLI template for a "course", now having used PreTeXt for (almost) all of my course materials this semester. While I don't use slides to teach from, I know there are plenty of folks who do, and I was going to include a slideshow as one of the course components.
This got me thinking about how these should be embedded within a course. Currently, all the other student-facing materials can be put into a "book", divided in chapters corresponding to different types of materials. I have a chapter of "course documents" (mostly just a syllabus), notes, worksheets, homework sets, etc. Thus all my materials for a single course are in a single repository, and there is a single target that builds all of them as a single pretext document.
Slide shows are different though. For one, you can't include a slideshow as a section in a book (although perhaps you should be able to??). So from the CLI perspective, each of these will be a separate target, with a separate entry in the project.ptx manifest. If you use a different slide deck for each day of a class, you might have as many as 60 targets that are slideshows!!
While I am pretty sure it doesn't work yet, it would not be too difficult to allow the CLI to build a "standalone" target with format slideshow. That would take care of the excessive targets in the manifest, although would require typing the path to the ptx file when compiling.
Alternatively, the CLI could always build all slideshows that exist in a particular folder, and create a landing page that points to each. More work for me, but if it is useful, I'm happy to explore this.
I haven't thought too much about a (core) PreTeXt way to manage this, but that is also an option. What happens if you include a slideshow element inside a book? PreTeXt could generate that slideshow and add a link in the place in source it is included. Or maybe there is a more general "collection" target that does something like that. I could definitely see an advantage to being able to xref to particular slides.
Just throwing out some ideas while they are on my mind. Not necessarily looking to work on this in the next month (but who knows?).