The idea is to separate the widget properties from the properties depending on the parent. This will work for childs of parents like sizers, notebooks.... but specially for wxAuiManager, that adds a lot of properties to it's childs.
An example of how this can work is shown in the attached picture.
I know that you don't have much time so, if you like the idea, I can help (...if I have time to do that...) and submit a patch.
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