Vertical Autozoom ⌃⌥⇧Z — Logic Pro keyboard command of the day

  Vertical Autozoom ⌃⌥⇧Z

Set automatic vertical zoom on. Similar to the zoom controls in the Tracks window. Vertical and horizontal zoom controls are at the top right of the panel.

Use the Sampler Zone pane in Logic Pro — Apple Support

Zoom vertical button: Switch between the maximum vertical zoom view for the currently displayed waveform section and the default zoom view.