SUMMARY I am making the tiling window script. For its use case, sometimes it is desirable to opt out of the behavior, when the window do not resize below its minimum size. It would be nice if the KWin provided a function to toggle this rule. See also: https://github.com/gikari/bismuth/issues/102
If you use AbstractClient::moveResize(), it will ignore the minimum size hints. In theory, applications should honor that, but many of them force the minimum size on the client side, i.e. they will paint window with the minimum size instead of what the compositor asked, which is a protocol violation that kwin_wayland doesn't check.
This bug was reported against an outdated version of KWin. We have made many changes since the. If the issue persists in newer versions can you reopen the bug report updating the version number.