SUMMARY The window decorations does not have a setting to disable the outlines that was added in this merge request: https://invent.kde.org/plasma/breeze/-/merge_requests/241 It seems the merge request originally had code that implements the option, but later was lost in the commit squashing procedure before merging into master. The code mentioned can be found here: https://invent.kde.org/plasma/breeze/-/merge_requests/241/diffs?commit_id=a1ac5ff39f627dde459b51cc8f97fa20ac7cf596#b90307d4d17ed0569466caf7b3554c6a45d6b2e3 SOFTWARE/OS VERSIONS Breeze: commit 8a91ef78d5069603369600ca1fc715f782d917fb and later
The merge request was later re-done to not have that setting in it after discussing it. *** This bug has been marked as a duplicate of bug 465948 ***