Hey Jon,
Thanks for the reply. I've been poking around and am not seeing a way to modify the standard buttons, just some additional ones.

For example, after enabling the standard buttons via:
  cfg.setIncludeStandardButtons(true);

the getItems call:
  List<ButtonConfig> existingBtns = cfg.getItems();

doesn't list things like insert, print, export, qc state, etc. Tried digging further into what
  List<ButtonConfigFactory> buttons = EHRService.get().getTbarButtons(ti);
but that doesn't seem to be it either.

Best I can tell, the standard buttons are added after this customizer runs so I can't actually modify them.

It's entirely possible I'm missing something here. Any suggestions?