A propos of this, does anaconda warn you may be doing something silly if you create a separate /usr partition in custom partitioning? Should it?
If /usr as a separate partition has always worked and doesn't now, it should probably throw up a warning, no?
At least Disk Druid should not be including /usr in the list of suggested mount points for a custom configuration.
We removed /usr from the list of suggested mount points a little while back, so you'd have to type it in yourself.
- Chris