There is an option to change the border color but not the thickness of the border.
Some themes come with rounded corners, and there seems
See the top right corner, there is gray shade at the corner rgba(0,0,0,0.2) - the color of the border.
The border for the title bar portion (i.e. top-left, top-right) can be eliminated so that the rounded-corners are preserved.
Though that seems less, it becomes more if the custom border thickness option is implemented and if border thickness increases to a notable extent.
There is an option to change the border color but not the thickness of the border.
Some themes come with rounded corners, and there seems
See the top right corner, there is gray shade at the corner rgba(0,0,0,0.2) - the color of the border. The border for the title bar portion (i.e. top-left, top-right) can be eliminated so that the rounded-corners are preserved.
Though that seems less, it becomes more if the custom border thickness option is implemented and if border thickness increases to a notable extent.