What the Mother describes in the Agenda is not psychic realisation, not even the spiritualisation or the Supramental realisation. All these came much earlier and can be found in the Prayers and Meditations as well as Conversations. What She is describing in the Agenda is the supramental transformation of the cells.
But how did you draw the conclusion that the disciples did not write about the psychic and spiritual realisation? Please read the memoirs of Amrita, Kapali Sastry, Amal Kiran and others.
Yes, there are people even now who have had both psychic as well as spiritual realisations and the cosmic consciousness. Why should they disclose it to you or just about to anybody randomly? If you are sincere seek them out with humility, meet them as a humble seeker and they may share some of the special gems including the psychic realisation if they wish. But you can’t shove a mike on their faces like an inquisitive reporter and force them to disclose their experiences to you simply to satisfy an idle curiosity. These things are not shared like that. The Mother too did not share it publicly. It is after decades that some of Her realisations are freely and publicly available.
By the way how does it matter whether anyone realised anything or not. It is enough that one has the aspiration and has faith in Sri Aurobindo’s words and is thereby willing to undertake the journey even if none before him believed or walked. After all the merit of a spiritual possibility is not decided by a vote as to how many or who all experienced it as if a headmaster is asking students to raise hands and confirm. Your questions shows an approach that will get you nowhere as it smacks of vanity and arrogance rather than humility and seeking.
About Savitri | B1C2-10 Condition of the World (p.18)