Only return one experience via global mbox per selector

[#1]

If multiple experiences target the exact same selector on the page, all experiences are still returned. Due to the selector conflict, only one of these experiences will actually be visible to the user while the others will effectively do nothing. This leads to additional unnecessary client-side processing and misleading A4T impression metrics.

Please only return the highest priority experience for a given selector.

[#2]

I do not think this would be possible since the initial call to Adobe will not have all of the potential selectors that are on the page. In addition, I like that target-global responds with more than one activity since it can cut down on other test areas on the page. Less network calls.