I would like you to focus on the powerful Preview Vicon that I called friendly "Spyder mode" for convenience. It works very good with one video track in timeline. However, in any cases you may have a few parts of a video on more video tracks and there, the  "Spyder mode" is complicated.
Moreover if you have many tracks on timeline (let say more than five?) with the "Spyder mode" you find the "x" coordinate on timeline but not the "y" (which track?).

This discussion is just to focus on a possible problem/solution.

I didn't find a name in the messages for that feature; sorry if I didn't see it. If any, can you (Developers) give a special name to this feature, please? Will be fine, I think.

I added screencast about it:
https://www.datafilehost.com/d/59aa2f9f

What do you think about, please?
Thanks

IgorBeg

PS:
Too many place where to write. (Maybe I am on the wrong place)