Reply to "Benchwork - Wiring - adding elevations"

I did not screw or glue it to the plywood and did not paint or seal it (mine is 'faced' i.e., water resistant on all sides).  It has not shifted, warped or otherwise moved.  The weight of the track, switches (which are only screwed  into the it and not the plywood) trains, buildings, accessories have kept it in place.   The climatically controlled environment indubitably assists in keeping things true as well.  I have made changes to the layout over the years and being able to pull it up and reshape it or place new sections in has worked well for me.