Microsoft is working on a new toggle that aims to make it easier for users to disable Windows 11-style rounded corners for browser windows in Edge. Microsoft already allows disabling and enabling rounded corners for browser windows within the settings. The “Use rounded corners for browser windows” option is available in the Edge Canary interface. It can be toggled on or off.
However, with the new Canary, Microsoft is apparently experimenting with a new easy option to turn browser windows on or off on the three-dot menu. This means users won’t need to go to the three-dot menu > Settings > Appearance. The change was seen by Desk Modder And you can see how the option will work in the images below. The left image shows the new toggle that is on the top right while the right image shows the change after the browser restarts with the toggle set to disabled.
Notably, this option is not available to everyone as it appears to be a controlled feature rollout. This feature may become available to everyone when it is ready for a stable channel release sometime in the future.