Is it possible to disable Mosaic view for certain (most) users?
So they can still change for 'listing_view' to 'album_view' etc, but not change to Mosaic view.
I was going to write 'Use a TALES expression', but that's only available on actions and thus the actions menu, not the display menu. 
Bit of a twist/ugly, but if there is no saner solution you could remove mosaic layout from the display menu and re-add the activation under actions (with a custom script to switch the layout).