Rounded corners and title bar #553

Hello

The "MS Edge rounded corners" flag has disappeared from Canary for some time now (and I suspect it will soon disappear from other versions as well).

Is there an extension or something else to remove this inner border that reduces the display of web pages ?
And while I'm at it, to reduce the width of the title bar (so that the tab touches the edge of the title bar when the window is maximized) ?

Basically, have the UI from a few months ago. I don't want to do what others have done and switch browsers.

Thanks for your help