Problem with duplicate fields in user model

[mirbon]

In file 'register.api.js', line 91:

    user.role = request.pre.role._id
    user.roleName = request.pre.role.name
    ...
    user = await RestHapi.create(User, user, Log)

why you need to assign the 'virtual' field 'roleName'?
Why is not automatically assigned when the user is created?

I have to add the line:
user.roleRank = request.pre.role.rank
to avoid an error in user creation, but is strange that the virtual field in not automatically generated.