2hrs later it's still reading assets. apparently 8.1 is busy rejecting all the 8.0 expression morphs and that takes TIME. The log is complaining about every expression I have installed for 8.0
I think this should work much quicker:
Load the G8 character as normal.
Save as a shape preset in the Zero Pose.
Apply the shape preset to the G8.1 dev character.
The same process for the Materials.
I think doing the shape and material presets separately is better than using a character preset that includes both, because a character preset will take longer too.