Yes, but maybe you can use the method in the Tk interface, to do the equivalent procedure in Tkx. Tkx is supported by ActiveState, and for that reason, it may be better, with better docs, etc. Have you asked on the Tkx maillist or forums?

If I had to choose only 1 toolkit now, it would probably be Gtk2. It works on both win32 and linux, and has a good underlying design.

See Re: Changing the geometry placement of Tk::Notebook tabs for an example of Gtk2::Notebook