Just a followup if anyone’s interested. I’ve decided to use a different plugin for the background slider. It’s called: “Full Page/ Full Width Background Slider”. It’s a much lighter plugin. Also, the Background Manager slider seems to possibly be querying the database on each slide change. I’m not sure. But if you have the site open in a different browser window, and then change the slides in the admin area in another browser window, the new slide appears, without having to refresh the browser.
How I set up the “FP/FW Background Slider” is: 1) I set 1 photo only for the entire site. 2) On the Home Page only I set multiple photos. This way, only the home page has a changing image slider. And the other pages only show 1 background image. I think it’s too much if all pages are constantly changing the background. Cheers!