With Z3 scrolling was added the ability to control the viewport, but only by scripting.
With this, you can control the viewport with just an FFC!
Only works in regions.

Requires std.zh

How It Works

Slap this on an FFC, specify a counter, then trigger the viewport control by setting that counter to 1. Stop controlling the viewport by setting the counter back to 0.
You can manipulate said counter with a combo that increases/decreases the counter when triggered, or with an SCC.

FFC Editor

D0 - Viewport Mode: 0 = absolute X/Y, 1 = offset X/Y, 2 = absolute X/Y (pan), 3 = offset X/Y (pan)
D1 - Move When Triggered: If in offset mode, 1 = will not apply this FFC's Vx/Vy/Ax/Ay/A. Delay until the script is triggered
D2 - X
D3 - Y
D4 - Counter ID: Counter with this ID will toggle controlled viewport when >= 1 (on) or = 0 (off)
D5 - Pan Speed 1: How fast in px/frame to pan to the destination
D6 - Pan Speed 2: How fast in px/frame to pan back to the hero
D7 - Allow Out-Of-Bounds: 0 = viewport will not go out-of-bounds, 1 = no restrictions

Example

Stab the bush to spawn a chest, and the viewport will pan to and from it.