How can I achieve proper shadow rendering for rounded frameless windows on Linux?

Developing an application launcher I face shadow rendering issues. While macOS handles rounded windows with shadows seamlessly, on Linux, the shadows for such windows appear to support rectangular windows only. Is there a workaround or a specific approach to ensure that rounded frameless windows display correct shadows on Linux? I tried to display a client side shadow but this ends up in a lot of work, like problems when maximized, uniform look etc. I'd prefer a proper system decoration solution.