Hi Anton,
The current VTK version in experimental (vtk9 9.5.2+dfsg2-1~exp4) looks good to me.
It was built with Qt6 GUISupport, but without ParaView support due to memory exhaustion on some build archs.
Most Level 2 reverse dependencies build fine now.
https://release.debian.org/transitions/html/auto-vtk9.html asl # OK
gdcm # TBD, FTBFS in sid
lammps # OK
liggghts # OK
mia # TBD, FTBFS in sid
odin # OK Simple patch needed
open3d # OK
opencascade # OK Simple patch needed
pcl # OK Simple patch needed
therion # OK
yade # OK
I did not test Level 3 and 4 reverse dependencies that depend on gdcm.
Given this status, can we request a transition slot and proceed with the upload to unstable?
Best
-Dominique