Hey, Ben - It sure did, the presets are applying very fast with no slow down. I would consider my problem resolved at this point.
Just an FYI for you and the team, though. I checked the Task Manager throughout testing the presets and noticed that, even with no backgrounds at all, MediaShout was taking 1.3 GB of memory after apply a preset to 9 units, up from 500MB when I first opened the program. This memory was not released even after I closed that particular set of slides (via "File" -> "Close"). I'm not worried about it on my side, but I just wanted to pass it as I thought it was interesting.
Have a great day, and thank you for your help!