I have just been onto support to see why UPN's do not pull through from Applicants in Admissions mgr, when students are transferred across to current. Apparently this is how isams is set up but this an unnecessary duplication of work for support staff when enrolling students.
Released 26.11.3.8: Admissions: Unique Pupil Number (UPN) field is now available on Admissions applicant General record.