Stacking/Version: Most possibilities with Master as top

[sinus]

If I have both, Stacking and Version, and I play with "Toggle Version stack" and "Expande" and "Collapse", to have for example all stack - members viewable (in the thumb-window) and Versions not displaying and so on, I spotted:

I have the most possibilities, when the top of the stack is the "master of the stack".
And also, if the top of the versions is the master.
Is that correct?

If for example the top of a stack is not a master of a version, I cannot use "Ctlr shift s" (while with the master of a version as top, it works fine).

This would mean for me, that I must (for me) set always the master as top of a stack.
I have not tested this, if the top is a proxy.

Sorry, I am in a hurry, maybe you cannot understand me, then excuse me please