Karl Voit has a revealing post in his UOMF series that explains how to generate a slide deck and supporting PDF from the same Org file. That has some obvious benefits, not least that it provides a single source of truth so you don’t have to worry about the slides and PDF getting out of sync.
It turns out to be pretty easy to mix LaTeX and HTML source in the same file without having them interfere with each other. For example, anything in a NOTES block will appear only in the PDF, not on the slides.
One of the interesting things about Voit’s method is that he likes to maintain just a few Org files that cover all his work so the slides and PDF are just one node of a large Org file that contains other material. If you like that idea, be sure to take a look at his post to see how he does it.
If your work requires you to give presentations and you like to use slides accompanied by a PDF for a handout that fills in the blanks, be sure to read Voit’s post. It really makes sense to keep everything together in a single file and Voit shows you how to do that.