I realize that what I offer here is not a solution, but might something like this help to avoid jumping into the problems with parallel mode?

var vp = moi.ui.mainWindow.viewpanel.getViewport('3D');
if (vp.projection != 'Perspective')
{
vp.projection = 'Perspective';
moi.ui.alert('Projection set to "Perspective".');
return;
}

Might there be someway of asking the user for permission before switching the projection setting?