Mathias, that is exactly what I was saying. It seems like a tricky flaw in the design to get around. Considering it's a free plugin, I doubt they are willing to invest the time. That is a smart solution for your autofocus, but not as useful without linking to the move targets. If you made an improved Sure Target, I would buy it in a second. And by the way, your layer placement scripts saved me literally days of work on this project. I am going to post it as soon as I am done, I think it is a good example of what your scripts can do.
For example, I had a sequence where the camera runs down a line of 10 products. I set up the products in 3d space aligned using 3D line layer placement plugin, then generated sure targets and used the same iExpression to match up the products and the camera targets. Then I only needed two 3D null controllers to change the entire camera animation, timing, and product alignment in 3D space. Notes that would have taken hours were almost instant fixes.
Anyway, I ended up making a full copy of the original camera rig and the first ten targets, moved the entire timeline of 253 layers ahead by 20 seconds and inserted the new clips at the beginning, cutting and pasting properties between the original targets and the new camera rig system. Then I transitioned between the cloned targets and the original targets in the old camera system where it crossed over so it was seamless. Although I had to counter-rotate the entire set at one point in order to loop back to the original coordinates. It took way too much time to figure that out.
-TG