Most functions defining menus compute once and cache the result...

... Except a few where project or plugin manager state or preferences are
needed to compute the items, so evaluation is delayed, often inside lambdas

Comment "Delayed evaluation" wherever there are exceptions

src/menus/HelpMenus.cpp

@@ -420,15 +420,11 @@ static CommandHandlerObject &findCommandHandler(AudacityProject &) {
 
 #define FN(X) (& HelpActions::Handler :: X)
 
-MenuTable::BaseItemPtr HelpMenu( AudacityProject & )
+MenuTable::BaseItemSharedPtr HelpMenu()
 {
-#ifdef __WXMAC__
-      wxApp::s_macHelpMenuTitleName = _("&Help");
-#endif
-
    using namespace MenuTable;
-
-   return FinderScope( findCommandHandler ).Eval(
+   static BaseItemSharedPtr menu{
+   FinderScope( findCommandHandler ).Eval(
    Menu( XO("&Help"),
       // QuickFix menu item not in Audacity 2.3.1 whilst we discuss further.
 #ifdef EXPERIMENTAL_DA
@@ -480,7 +476,8 @@ MenuTable::BaseItemPtr HelpMenu( AudacityProject & )
 #endif
       Command( wxT("About"), XXO("&About Audacity..."), FN(OnAbout),
          AlwaysEnabledFlag )
-   ) );
+   ) ) };
+   return menu;
 }
 
 #undef FN