The current developer forum is only for those working on paraview itself. As a paraview developer I have tried asking for help there and I seemed to be ignored. It would be nice to have a stack overflow like page for the class of paraview developers working on filters/sources/3dwidgets/writers and not necessarily the paraview application. Its just a matter of creating the page shouldn't be too bad.
It is totally OK to post such questions to ParaView developers. As it is on the ParaView users list. Developers follow both. Also, question more specific to algorithms can go to the 2 VTK lists, where is it more likely to receive more response due to a larger number of members. Keep in mind that ParaView is simply an extension of VTK and all of the algorithmic core is in VTK.