Roting Loader Icon/Gear when a view is loading

With some nested field collection views (.e.g list views with multiple database) the list view taks 5 to 10 seconds to load. This is not only for new users but also for me confusing each time, since it currently shows as if the list view does not exist.

So I suggest a Loader Icon/Gear when a view is loading.

Related, more severe:
A similar but more severe issue of delay but also freezing happens when updating the databases (views items) of a collection field, that takes even more time (sometimes 30 to 60 seconds). I know this is because of the amount of databases and complexity, but it would be nice to have a loader icon also instead of the whole screen freezing.

Possible solution: better caching method
Given that the two issues above are in my experience the only time-consuming bottleneck I have seen in fibery, I suggest to implement for both a better caching mechanism (preloading cache, loading in the background with a notice (‘..updating view’)
Benefit: users can still choose to navigate the view while its updating in the background.

How many databases you have selected for this view that loads slowly?

4 databases, plus one recursive