It seems like some pages, including the extensions page and developer tools, should follow the system's display scale.

[Githubmaniak]

While the previous Kiwi Browser would follow the system's scale, whether it was the extensions page or the developer tools, Ultimatum ignores the scale and appears small.

[Githubmaniak]

Also, you can't play YouTube videos in full screen.
When I play a video on YouTube and switch to full screen mode, the video freezes and won't play again until I refresh the page.