I like working with the Lens Flare in Motion better: Library, Generators, Lens Flare. For example, it adds an Add blend mode by default. The Streaks are better positioned. If you want a more serious lens flare I recommend getting a 3rd party plug-in. The FCP / Motion Lens Flare is limited in what it can do. As for the Streak Map, which is an image well that displays a thumbnail of the map chosen for the streaks of the lens flare. You can place the clip the lens flare is over in that well. It will change the pattern of the streaks and animate it based on what is in the clip, be careful using this. Take a look at the image below to show the difference.

Hope this helps and best of luck.
Stephen Smith
Utah Video Productions
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