Thank you for reaching out to us. In short, what you want to do is unfortunately not possible.
To unpack things a bit, I understood your question as such that you have multiple view panels in your layout and each view panel contains multiple views. The screen below shows two view panels with four views each for example.
You then want to toggle a view panel from showing all its views (depending on the panel layout) to singular one, e.g., "minimize and maximize" the Perspective view in the second panel. For that you wanted to use
c4d.CallCommand(13640) and therefore need to set the active view (the view with the grey border).
Internally, there is a non-public method called
BaseDocument::SetActiveView which handles setting the selected viewport and one has more or less all tools in the Python SDK to replicate it (you more or less just have to set
BIT_ACTIVE and send some messages). And while doing this will have some effect on the selection state of viewports, it will not be identical to what you can achieve with mouse interactions, and running then your
CallCommand(13640) on such 'semi-selected' viewport will not have the desired effect.
In the end, the viewport selection state is bound to a very specific call chain in our internal API. Which is probably the reason why the method
BaseDocument::SetActiveView remains non-public.
FYI: This is not a Python issue, the same applies to C++, I tried it there too, to the same effect.