With Use Preview Bounds on, a bounding-box handle drag scaled the art by
the ratio of the visual box, so margins that stay (a stroke with Scale
Strokes & Effects off, an Offset Path reach) or scale by another factor
moved the opposite visible edge: dragging the right edge of a square with
Offset Path 10 from 210 to 310 left its left edge at 98.33 instead of 90.
The Selection tool now previews object.setBounds with the dragged visual
size and the opposite handle (with Alt, the center) as the reference
point, so the scale is solved from the geometric box and the margins the
visual box adds, for strokes with Scale Strokes & Effects on or off and
for geometry effects. Shift and Alt drags follow the same rule; a drag
that flips the box, and one with anchors selected, still scale by the
matrix. A previewed object.setBounds runs as object.transform with the
transform it finds, so Transform Again repeats the drag and the journal
holds that transform. The drag transforms a path of a compound path
selected on its own, as object.transform does, and leaves the art at
least 1e-4 of its width and height.
Angelo Bernardini