Scripts can already use GetTopScreen to get this. However, that function
also returns data that may not be what's wanted. For example, commands
can be run on screens that aren't on top (eg. via broadcasts). So, using
GetTopScreen as a fallback for LoadingScreen may cause latent bugs;
screens should behave properly even when they're not on top, even if
they're using queued broadcasts to kick off animations, etc.
Glenn Maynard
3a63f5b7ef