What is expected of the guest curators?
That they help define the communal basis of the individual projects.
That they actively build up this basis too, by inviting mentors and speakers, by organizing workshops and preparing public output - publications and/or other media.
That they bring with them and contribute their own (artistic) projects so as to really be part of the group. The only relevant difference would be that their projects already have a clearer 'meta-context' which will facilitate the gathering of the participants' projects.
That they spend between 8 and 12 working weeks in person with the training programme so that they can guarantee continuity, both in the research and in the feedback emerging from the training.