Are you still porting this to Source 2

Actually you can export camera movement to BVH and then import it into AE or any software you like using these - https://github.com/advancedfx/afx-sfm-scripts

You can even render the 2nd clip with no lighting or anything too, so you can speed up the process

Hope this helps!

Just for how to use these motion trackers, for new people into editing their animations, under these circumstances:

-Unless you have a powerful computer and a big disk size to hold a whole video without lag:

- You would have to go for Image Sequence, and also take off the checkmark for separate audio file via WAV

- Change the file save location to an empty and rememberable folder to hold the images.

1) Render two versions of the same shot, but one at a time. First, you render one version with the motion trackers, and then stitch them together. The best way to do it is through Blender's Video Sequencer. There are videos on how to do it, and it is simple to do. Follow it correctly, and you should have it good to go.

2) Render the second version, but without the motion trackers. This way, once you place the motion trackers and essentially 'bake' the animation through the video editor (most potent is After Effects), you can turn off the visibility of the first version and turn on the visibility of the second version.

3) Parent the Trackers to like an image that @Mittens has exampled. The best way, in my opinion since I'm a FNAF Animator and whatnot, is lyrics of a song. They will do great if you have the lighting right and the song synced up.

@Tiretracker Super useful for green screen effects, or anything visual added in post

No idea what I'd use motion tracking with but this looks handy for configuring the aperture