Most stream commands are not available in glvis-js/pyglvis because aux_js.cpp/display is handled differently.

See: GLVis/pyglvis#49

Unfortunately, valuerange is the only other command that works - glvis-js has different machinery for handling the stream (glvis/lib/aux_js.cpp/display). In particular, see these lines. As an example, you can add zoom 50 at the end of a .saved file and open it with glvis vs glvis-js.