demm No, only thing that uses grantlee for kf6 (grantlee-qt6) is kdevelop build from a draft kf6 port. The 2 you mention do not use grantlee -qt6 in the build repo, they properly use ktexttemplate (through grantleetheme kf6).
demm Yep, that is the port kdevelop is now building from (before all moves to stable, a decision will be made whether to stick with kf5 for kdevelop and add some kind of kf5 version of libkomparediff, or if the kf6 port is good enough). https://github.com/KaOSx/apps/commit/c665f6777e22bde58eb8d29b75a00f0f8f32fb04#diff-668bc9ab6f0a70bbcd1f6e97040efe9301b958e7a5024a091b38e27abadf2ad1R25
bvbfan Calligra suite have to be recompiled, all executable crash in plugin loader. Qt5 applications doesn't follow the plasma theme (breeze here), breeze-qt5 or similar have to be provided. https://github.com/KaOSx/apps/blob/master/breeze/PKGBUILD#L28C10-L28C20 It shouldn't be disabled, it will provide plugin for Qt5 breeze style
demm Breeze5 is added (separate package). Also added is kdiagram5 so all kf5 apps that need it now depend on that kf5 version.
bvbfan Everything seems fine now. marble marble: error while loading shared libraries: libvpx.so.8: cannot open shared object file: No such file or directory libvpx 1.14 provides libvpx.so.9 so probably when libvpx is updated marble should be rebuild
demm No, you updated too soon 🙂 Most was build locally, but I need the buildserver for the QtWengine packages, update again, and you will get the needed qtwebengine rebuild (Qt5 version for marble).
bvbfan Can we have also https://community.kde.org/Plasma/Plasma_6.0_Release_notes#Tars_that_need_Qt5_and_Qt6_build plasma-integration and kwayland-integration qt5 build kwayland-integration remains Qt 5 only as its features have been moved into kwindowsystem, this is still released and should still be packaged for compatibility with Qt 5 apps.