Dynamic Zoom and real keyframes: boxes for speed, diamonds for control
'If your playhead is not on top of that keyframe when you start adjusting the settings it will simply add a new keyframe.'
Dynamic Zoom: Inspector toggle (goes red), zooms out by default - Swap to zoom in; overlay from the viewer's lower-right menu shows a green start box and red end box; drag corner dots to scale, drag inside to move; set green at the first frame, red one frame from the end; same size in two places = a pan; Ease In/Out exists, he prefers linear; a shorter clip zooms faster. Keyframes: the diamond beside any parameter (the top diamond keyframes all); Show Keyframe Tray at the timeline's top-left, drag the divider up; box-select diamonds to move them together; the playhead must sit on a keyframe to edit it - snapping (N) - or a new one appears; switch Keyframe Lanes to Keyframe Curves and pick Linear, Ease In, Ease In and Out, Ease Out; Shift-drag changes only timing (left/right) or only value (up/down); for an OFX parameter such as Zoom Blur, three-dot menu > Display Selected Parameters; a standalone Keyframes panel offers the same. Worked example: rotation keyframed to hold a drifting horizon level.
Every later effect - ramps, bars, blur, colour over time - is these two tools.