[:?:] How to manage the sticker seperately

I am trying to evaluate the docking pane library.

Our task is the following:

We need to implement several pane where some of them could not be docked together but only to the main frame. For this, I would need to manage the stickers but they seem to be protected. Is there a way to implement such functionality with your library?

For example here are different behavior we are trying to implement, Pane 1 and Pane 2 could be docked together and also to the mainframe. But Pane 3 could only be docked to the Main frame directly, and could not be docked to any other pane directly. Another behavior we are looking is where Pane 4 and pane 5 could be docked together and also to the main frame, but in the event where one of them would be already docked to the main frame(lets say pane 4), the other pane (pane 5 for example) could only be docked over pane 4. So in any time pane 4 and pane 5 would not be docked at 2 different places on the main frame (So to implement a docking area for pane 4 and pane 5).

I have also Another question, in the event where we would need to change the library to implement special features, can it be done via your license agreement.

thanks