All things with an UpdatePrefs() message listen for an event...

... Still to do, improve the handling of updates of only subsets of the prefs

src/prefs/GUIPrefs.cpp

@@ -366,6 +366,12 @@ wxString GUIPrefs::GetLang()
       return {};
 }
 
+int ShowClippingPrefsID()
+{
+   static int value = wxNewId();
+   return value;
+}
+
 PrefsPanel::Factory
 GUIPrefsFactory = [](wxWindow *parent, wxWindowID winid)
 {

src/prefs/GUIPrefs.h

@@ -67,4 +67,7 @@ class GUIPrefs final : public PrefsPanel
 
 /// A PrefsPanel::Factory that creates one GUIPrefs panel.
 extern PrefsPanel::Factory GUIPrefsFactory;
+
+int ShowClippingPrefsID();
+
 #endif

src/prefs/PrefsDialog.cpp

@@ -850,9 +850,6 @@ void PrefsDialog::OnOK(wxCommandEvent & WXUNUSED(event))
    // LL:  wxMac can't handle recreating the menus when this dialog is still active,
    //      so AudacityProject::UpdatePrefs() or any of the routines it calls must
    //      not cause MenuCreator::RebuildMenuBar() to be executed.
-   for (size_t i = 0; i < gAudacityProjects.size(); i++) {
-      gAudacityProjects[i]->UpdatePrefs();
-   }
 
    wxTheApp->AddPendingEvent(wxCommandEvent{ EVT_PREFS_UPDATE });