Is it possible to run an Illustrator (or Photoshop) action without running the processes for displaying it? I assume this would speed up the performance—or maybe this is minimal.
You can run illustrator and photoshop hidden via the COM interface (Visual basic) on Windows. There is however no speed benefit that i have noticed, inDesign is in fact a bit faster. Mostly because it has a better designed and more modern api.
Scripts are faster than actions anyway, as they do not echo individual steps like actions do. But if your intention is to run actions then calling actions on hidden window is just as slow as it is without the update. There is a intentional slowdown in actions that is independent of your refresh rate.