Linked Dimensions (Constrain Proportions) for Frame Size Fields Sequence Settings

This is an embarrassing omission that has persisted for far too long. Every major image and video editing application on the planet - including Photoshop, After Effects, DaVinci Resolve, Final Cut Pro, and virtually every other tool in existence - provides a simple chain-link icon to constrain proportions when resizing a canvas or frame. Premiere Pro does not. Not in Sequence Settings.

The result is that any editor who needs to change their sequence dimensions while maintaining aspect ratio must stop their workflow, open a calculator, do manual arithmetic, and then type two separate values. In 2026. While paying a monthly subscription for software that Adobe markets as professional.

This is not a complex feature request. It is a checkbox. A chain icon. A single constraint toggle that ties the width and height fields together so that changing one automatically updates the other. The math is trivial. The UI pattern is decades old and universally understood. Heck, you even have it when exporting the video.