The SPA app can load faster then the mgnlRefresh is added to the window, this will cause bugs if the app tries to use mgnlRefresh - but mgnlRefresh is not available yet. Namely, the green bars won't get rendered.

In practice, this problem won't occur that often because the SPA app will be also be making a call to the REST endpoints to load content before calling mgnlRefresh. But it can happen if the REST response is faster then the mgnlRefresh being added. 

Or a developer might have hardcoded some json fragments and might not make a REST call during some testing for example.