How to tune nuitrack.conf

I have an issue that hand tracker lost hand, when user’s hand and shoulder is overlapped against camera.
For this issue, I would like to tune Nuitrack configurations, mainly RealSense post processing filters.
Next picture is our test environment using RealSense Viewer, in this case, hand tracker sometimes notifies no hands.

How should the parameters be tune ?
I’m using RealSense D415.