@Diederik: confirmed - after toggling off node snapping Inkscape follows the bbox preference (set to 'Visual') and uses the edge/corner of the visual bbox as fixed anchor for resizing/scaling while the grid is visible.
@Diederik: confirmed - after toggling off node snapping Inkscape follows the bbox preference (set to 'Visual') and uses the edge/corner of the visual bbox as fixed anchor for resizing/scaling while the grid is visible.