Qt for macOS maintainer here.

We've tweaked our styles to take the new design metrics into account, and fixed or worked around issues where we've seen them. We don't integrate with NSGlassEffectView and friends yet. If you find any issues in recently released version of Qt 6.10, 6.8 or 6.5, please report them upstream, thanks!

See also https://www.qt.io/blog/qt-on-macos-26-tahoe