It would be great if there were a way to manually track three joints and then assign an angle tool to map onto those joints. I find the accuracy of the linear tracking is better and easier to work with (especially because of delete path after this point) than the angle tracking. If I could lock the origin and handle bars to already tracked points, it would give me a better angle kinematics and angle-angle plots without having to have many overlapping angle drawings on the picture.
Yeah the current situation is not ideal… For me the priority should be to make the angle tool (and other trackable tools) user interface be as convenient/capable as the trajectory tool. The other big issue at the moment is that we can't easily change the sizes of the search and pattern boxes.
Maybe one way would be that when you click on "Start tracking" it creates 3 temporary trajectories objects that you can interact with as normal trajectories, and when you click "End tracking" it merges back the trajectories data into the angle points timelines.