Accessing the hotspot collector, in a scenario where iFrames is overlapping the page completely, or multiple iFrames overlapping each other, can sometimes be impossible. The reason is, that the hotspot collectors are displayed on the very same position.
In GRAVITY version 1.12 (and higher) content owner have the possibilities to disable GRAVITY (in edit mode) for each iFrames. Once a content owner is in edit mode, he can right klick on the top hotspot collector and deactivate GRAVITY for the corresponding iFrame.
Every GRAVITY Server (version 1.12 and higher) has demo page, with an iFrame placed over a page each containing a table where you can add and remove rows. You will find that page under the URL:
To test the feature, just GRAVITY activate that page and add a row for each table. There is a button under each table to perform that action. Place a hotspot to each new row. Then delete the rows, containing the hotspots, and go in GRAVITY edit mode. Then you will have two hotspot collectors over each other, and you might test the feature.