Fancier conferences put up two projectors to let the audience see the slides. But the presenters still look at their slides on a notebook on the podium, or in some cases on a monitor on the floor below their stage.

How about adding a projector that projects on the back wall, just above the heads of the audience, for the speaker to see their own slides? Then they can roam the stage and see the slides without losing eye contact with the audience. They may not be able to see clear detail on the slides but they shouldn't need it.

It's true this does not work as well for "Presenter mode" which shows the speaker a different display on the notebook from what is seen on the projector, both because most notebooks don't have two video outputs, and also because you don't want to give the audience access to your notes and the title of the next slide as is often shown in presenter mode. However, not too many use this and it's not usually the end of the world if somebody can look back and see the notes.

You also want to show the speaker a clock. If that can be overlaid on the rear screen, great, but this can also be done as a different screen with a big clock. Projectors and screens are small enough to make this workable at fancy conferences.