#4757 gives a blend the Xy written after its record. When the blend is a
layer's last object, the layer's own state block (Xy, Xd, 7 () XW, LB)
went to the blend instead, and the layer stayed opaque. The blend's state
is now tentative like a mesh's (#4748): its own 6 () XW confirms it, the
layer's LB gives it to the layer and the blend keeps what it had.
Also records the .ai/EPS audit fixes under G9, the File formats row and M4.