All files are in the Github repo, and documentation in Wiki if needed.
To reproduce:
- launch SH3D (plugin installed)
- launch 3D view -> virtual tour
And it's buggy.

But if you continue:
- generate sb3 file
- launch ScratchOffline
- open sb3 file
- launch extension from ScratchOffline
- move in SH3D virtual view
and then it resolves pb.

Thanks a lot for helping!