Extending a camera track in PFTrack

If you have tracked a shot in PFTrack and then the shot gets extended and you want to extend your track, but keep the old solve, here is the workflow which worked for me.

1. Import the extended clip
2. Copy your node tree in PFTrack. I created a new Node Page using the P+ button.
   
3. Paste your node tree into the new node page. I do this so that I don't accidentally overwrite the existing solve.
4. If you have any User Tracks, select and export them.
   
5. If you have any Auto Tracks, select and export them as well.
6. Connect the new clip with the extra frames into the top of your tree.
   
7. When you connect the new clip, the User Tracks and the Auto tracks will not work anymore. Select all the User Tracks and delete them. Then Import the tracks you exported in step 4
   
8. Do the same with the Auto Tracks.
9. Your User Tracks will now have keyframes only where they were previously tracked. You now need to track the un-tracked frames for all of those User Tracks. Select them and press the Track button in the direction you need to fill.
   
10. The Auto Tracks will also need to be tracked for the missing frames. Simply select them all and press the Auto Track button. Select 'extend' when the dialogue box appears.
11. You now have all the trackers in 2D, they need to be solved for 3D. Go to the Camera Solver node and press the Solve Trackers button.
    
12. Now you are ready to extend the camera solve. In the Camera Solver node, press the extend button in the direction you need. The camera solve will extend out to the new frames and you should now have a camera for the whole shot which does not deviate from the old solve.