I have a few cases that are like yours, with many .pdf’s that I don’t want to show immediately. Instead of embedding them, I link to them (remove the exclamation mark (!) before the link). Hovering or clicking let’s me see them, but the default is that they are not visible, except for the link. It does mean the extra step of creating a note to hold each pdf (or a group of them I suppose), but it does work. I look at it as having some choice in the matter.
Hope this helps.
