This is due to a flattening of the data model in package/utils.go: getPackageUseflags. It returns a list of models.useFlags and later during template expansion we just say "these are all associated with {{ (index .UseExpands 0).UseExpand}}". There is a TODO to group-by, we should likely just change this to a map[string][]models.useFlag data struction. Then in the template we just iterate over the keys and for each value, emit the flag.
*** This bug has been marked as a duplicate of bug 717772 ***
This bug is fixed in prod. -A