In jQuery mobile source code find the code:

print("code sample");

$.mobile.zoom = $.extend( {}, {
    enabled: !disabledInitially,
    locked: false,
    disable: function( lock ) {
        if ( !disabledInitially && !$.mobile.zoom.locked ) {
            meta.attr( "content", disabledZoom );
            $.mobile.zoom.enabled = false;
            $.mobile.zoom.locked = lock || false;
        }
    },
    enable: function( unlock ) {
        if ( !disabledInitially && ( !$.mobile.zoom.locked || unlock === true ) ) {
            meta.attr( "content", enabledZoom );
            $.mobile.zoom.enabled = true;
            $.mobile.zoom.locked = false;
        }
    },
    restore: function() {
        if ( !disabledInitially ) {
            meta.attr( "content", initialContent );
            $.mobile.zoom.enabled = true;
        }
    }
});

and delete the lines: meta.attr( "content", disabledZoom ); and meta.attr( "content", enabledZoom ); then it will work without any flicker.