Since, to the best of my knowledge, Sibelius 2.x does not offer a C++ plug-in interface like Finale does, it seems to be impossible to create anything similar to my huge TGTools plug-in collection that would work with Sibelius, and therefore I am not interested in evaluating Sibelius any longer.

NB: The Sibelius "Plug-Ins" are forced to use their internal script language, which is nice but not powerful enough.