This is just a wish for an aesthetic improvement, but given that the window decoration, buttons, and similar elements all have rounded corners, the squared-off notification pop-ups look out of place (and uglier, to my eye). Would be nice to round them as much as e.g. the window decorations.
The corners, at least the shadow, is slightly rounded, no? Feel free to use a different Plasma theme, there are plenty of options to download from the internet.
Maybe, but certainly not as rounded as the default window border, window decoration, and buttons. Might be worth doing a user poll to see what is aesthetically preferred.
Michael, please get in touch with the kde visual design group and discuss it with them.
Will do. Thanks.