Hello ! So I’m trying to personalize gnome and for the moment I added blur with the extension “blur-my-shell“. When windows are minimized it’s okay that they overlap and it’s normal that the blur effect blur the overlapped ones but is there any ways to make invisible the unfocused windows when the focused one is in full screen ? Maybe I will need to make my own extension and it’s okay but if there is some ways to do it that I didn’t found then It could be really cool !
I doubt that this is possible because blur is not supported by GNOME. So either you can make a request to the author of blur-my-shell, or you can create your own extension. Obviously, the developers of GNOME Shell certainly know if it is possible to get what you want with an extension.
This means that if you have problems with blur, which is provided by an extension, GNOME devs won’t solve them. At least, that won’t be their top priority.