We tried QT_DISABLE_DEPRECATED_UP_TO with 0x700000 and found that the WindowType::MaximizeUsingFullscreenGeometryHint is deprecated since 6.9.

Output of qmllint

 Member "MaximizeUsingFullscreenGeometryHint" not found on type "QtObject" [missing-property]
	flags: Qt.Window | Qt.MaximizeUsingFullscreenGeometryHint

But because of 69fa60518c222605df26bbc10f4c1aeba2ebcdd2 qmllint cannot find this with 0x060902. Seems QT_WARN_DEPRECATED_UP_TO is 0x070000 by default. But this cannot be checked by qmllint.

Seems we are forced to use 0x700000 to found those issues. Otherwise we release new version with already deprecated code. This is a strange behavior. If new code replaces something it should be deprecated in that version and not in a future version.