I don't know if this repository is still active or not, but I have found a solution for the NullReference problem (supposedly preventing usage on Linux, but I am on Windows and got it too).

The problem is at the end of Start() which sets current mode which eventually bubbles to GetTrackedVessels which crashes (before setting render to true). I don't know unity, maybe SpaceTracking class is initialized after the start of this Addon, but patching the code to ignore nulls helped and made it working for me again.

ManeuverQueue.txt