Geometry

zScale

Batch scale

zScale scales the selected objects in a batch. It supports uniform and non-uniform scaling and lets you choose one, two or all three axes.

Quick start

Run zScale. The dialog is titled Batch Scale.
Select one or more objects.
Adjust SETTING and FACTOR.
Bake applies the scaling. Cancel discards it.

SETTING

Scaling Mode: Uniform or Non-Uniform.
Axis X / Y / Z: switches that turn scaling on or off for each axis. All are on by default.
Align: World or CPlane. The coordinate system the scaling refers to.
Base Plane: Bottom, Volume or Top. Where the scaling base point sits in the bounding box: at the bottom, at the volume center, or at the top.

FACTOR

Scale X / Y / Z: the scale factors. You can type a simple math expression.

How the settings work together

In Uniform mode, changing the value of any enabled axis updates the other enabled axes too (priority X, then Y, then Z). An axis that is not enabled is locked at 1 and grayed out.

Good to know

Only one dialog can be open at a time. Running the command again brings the existing dialog to the front instead of opening a new one.
Every object is scaled about its own base point, not about the common center of the whole selection.