My current site uses a lot of custom menus, created via SDA. At present there is no way of knowing if the user's environment is live, test, development or whatever and I'd like to use a message literal to provide a header line in the top row of all menus making the environment explicit. All I could manage today was a MSGCON which obviously pulls in the literal at compile time, meaning each environment would need its own menu. If I manually add a MSGID keyword, it gets deleted when the menu is compiled.
I remember this being an issue years ago. Perhaps someone reading this has found a way around it.