Sensitive user attributes in a federation

GPII is working on improved accessibility to the Internet and received an NSTIC grant for this work.
Users with special accesbility requirements due to disability, age or other reasons might benefit from a capability of having their UI preferrences sent to an application server. This could be achieved with configuring the user's devices, or bind that information to the user's identity. Considering these preferrences as sensitive private data this might have an impact on attribute federation.