Correct- programmatically, its quite easy to do/keep updated. The issue is making a consistent/non confusing interface. UIs tend to become less usable overall, when things are not consistent. In this case, there are two different scenarios:
- A manual dock that is not being used to switch scenes. Clicking on the items in the dock is only done to pull up the context menu options, or use the buttons on the right side. In this case it would not make sense to switch the active item to the active scene.
- A manual dock with the "clicking switches scenes," option enabled. Now when we click on a scene we are switching the active output, and it might make sense to switch the active item.
But to further complicate things, the manual dock can (and often does) contain non-scene items. So what if I am currently working on changing parameters on my face cam source which I have in my dock, seeing how those changes affect its rendering in various scenes. If we have the manual dock switch its active item, every time I change a scene, it is going to de-select the source I want to be editing (the face cam in the manual dock). This can make things quite confusing/frustrating.
That is not to say changing the focus is a bad idea. I just need to think a bit about how it would work, while keeping things consistent.