For example, there's an image viewer software called HoneyView. It can be set to borderless mode, but on Win11 it has square corners. So, I added a rule to change it to rounded corners, which resulted in the thin border of Win11 appearing.

However, its behavior is inconsistent with native Win11 windows: when selected as the focus, this thin border does not change to the theme color like native windows, nor does it show a shadow behind the window.

Additionally, if HoneyView's window is made fullscreen/maximized, it still shows rounded corners and outlines at the outermost edge, instead of filling the screen with square corners like a native window. Is this because the software's fullscreen is not the standard fullscreen/maximized as defined by Windows?

Since it can't behave the same as native windows, is there any way to simply turn off this thin border of the native window to make it look nicer, without this glaring outline?

HoneyView original window：

HoneyView with MicaForEveryone's rounded corners：

I found that PotPlayer has a similar issue. When set to rounded corners, a gray outline appears whether it is selected or not. However, unlike others, it has a shadow when focused. Based on this, I believe the shadow might depend on the software's own implementation and is unrelated to modifications by micaforeveryone. Maybe we only need to discuss the outline.