Slurs and ties don't follow Staff Change offset

Staff Y offset (as in Staff Type Change inspector "Offset") is not being applied to slurs and ties.

To reproduce:

1) Apply a Staff Type Change text in the middle of a staff
2) Create some music with slurs and ties at that location
3) Change the staff type change "offset" in the inspector
4) Notes move up and down along the offset but slurs and ties are left behind