So, I’d just use Samba or whatever to share it too. It’ll do a number of things better, like letting software render for an appropriate page size in the printer automatically.

However, OP is specifically trying to avoid using this route, because he’s concerned about people having trouble with setting it up on their client devices, so he just wants to bypass all that and to have a Web UI where one uploads the document after it’s been rendered to a PDF or similar.