Right. It's not in Advanced Preferences, though. The only option under Advanced ->v Playback -> GEP is "Show error message popups", and I don't see GEP anywhere else in Advanced.
Edit: Weird. I uninstalled foobar2000 completely and reinstalled from scratch, and suddenly the option is there along with a bunch of SPC options. I have no idea why I needed to reinstall, but it worked. Thank you.