LTI interoperability issue 2: Names and Role Provisioning Service

Please can I recommend that the spec be made explicit about whether a platform must respond to requests to this service with all users enrolled in a context rather than just a subset of those with one or more specific roles. As already reported in a separate thread on this forum (see https://www.imsglobal.org/node/196841) I have found at least one certified platform which only returns learners and not instructors. This can be very unhelpful for some tools. Personally I think the service should return ALL users who are able to launch the tool from that context, nit just some of them. Thanks.