Quickly enable/disable motionblur knobs in all kind of nodes. You can select them or link by classes. Just do it and enable/disable your gizmo to turn on/off motion blur.

Select nodes and click 'Link / Unlink Selected MB'. Turn motion blur on/off by enabling/disabling gizmo. Also can mark classes whose motion blur you want to enable/disable and click 'Link / Unlink selected classes MB'. You can break all links using 'Unlink All MB' button.

I recommend setting motion blur in nodes and after that linking them to this gizmo. You can change values when the gizmo is linking, some keyframes will appear, but they do nothing. This gizmo is specially useful if you use D shortcur.