Can we get an event for when gmpx-api-loader is done loading?

Can we get an event fired when gmpx-api-loader is done loading "maps" and other libraries? Currently there's no way to implement a "initMap" type function reliably.

For example, on Safari, once the page is cached, the window.load event fires before the Google Maps library is finished loading/initializing. As such, I cannot access google.maps.* functions.

I had to resort to polling (yuck!) for now.