Viewer lock command but no button?

Am I to understand that there will be a command to lock the viewer pane but no actual button on the pane to do the same ?

From the original thread " Lock/pin viewer pane to certain file - #2 by Jon ":

If you want a toolbar button that only appears while the viewer is visible, to avoid wasting space when it's not:

@hideif:!Set VIEWPANE=Toggle

but this would be a button on a regular toolbar but not within the viewer pane interface itself ?
To be honest, that seems kind of out-of-place and clutsy

I do have a viewer pane button to turn it on
I suppose it would work if I include the lock as a part of a menu button, if that is the wording