The short answer is no. The longer answer is a bit more interesting.
The LEDs and the cameras on the Leap Motion Controller are integrated on the hardware level to be closely synced. This is because the LED flash lasts 1/2000th of a second, while the framerate on the controller goes up to about 120 frames per second.
At the end of 2018, we did release an API in an experimental installer called LeapUVC, which allows for access to low-level camera controls that were previously never permitted to the public, such as LED brightness, gamma, exposure, gain, resolution, etc. http://blog.leapmotion.com/leapuvc/
Critically, however, making these camera controls available to the general public is intended to open up other types of computer vision projects. The Leap Motion software handles camera controls around its own hand tracking, and messing with them at one level is pretty much guaranteed to foul up the tracking software’s ability to accurately interpret what the cameras are seeing.