I don't currently have access to my regular system, but on an old laptop (doesn't support Vulkan), disabling the extend to screen edges setting doesn't shrink the panel/dock.
The only visible change is seen if the panel isn't floating, and disabling the setting causes the corners away from the screen edge to be rounded.
I didn't originally want to create this issue because of the very old laptop, but I saw a post on Reddit that says that the panel doesn't shrink (COSMIC on Fedora 40).
The last time I tested on my regular system it worked, so I'm not sure if this still works there, or if it's related to hardware, or if it might be caused if COSMIC is installed (not upgraded) recently.
Unrelated but don't want to create a separate issue due to the very old hardware:
The app thumbnails on the minimize applet don't show up on this laptop (i.e. there's a larger app icon inside a square outline and the same smaller icon in the bottom right corner).
I don't currently have access to my regular system, but on an old laptop (doesn't support Vulkan), disabling the extend to screen edges setting doesn't shrink the panel/dock. The only visible change is seen if the panel isn't floating, and disabling the setting causes the corners away from the screen edge to be rounded. I didn't originally want to create this issue because of the very old laptop, but I saw a post on Reddit that says that the panel doesn't shrink (COSMIC on Fedora 40). The last time I tested on my regular system it worked, so I'm not sure if this still works there, or if it's related to hardware, or if it might be caused if COSMIC is installed (not upgraded) recently.
Unrelated but don't want to create a separate issue due to the very old hardware: The app thumbnails on the minimize applet don't show up on this laptop (i.e. there's a larger app icon inside a square outline and the same smaller icon in the bottom right corner).