> It just seems like a logical next step would be to outline instructions for a more secure setup using something "standard" like nginx instead of leaving it as an exercise to the user -- who may not be so tech savvy.
Maybe this is what you're looking for:
https://jellyfin.org/docs/general/networking/
Edit: On desktop, the sidebar is visible which includes links to instructions for Nginx, Caddy, Let's Encrypt, and some other things. I didn't realize at first because I looked at it on the desktop, but on mobile it seems you'll need to hit the hamburger menu to get to those links.