Where does it say that the UK JAA FI(r) cannot operate unsupervised?
JAR-FCL 1.325 (b)
Restrictions. The privileges are restricted to carrying out under the supervision of a FI(A) approved for this purpose.
ANO Schedule 8
Restricted Privileges
(3) The privileges shall be restricted to carrying out under the supervision of the holder of a flight instructor rating (aeroplane) approved for this purpose:
(a) flight instruction for the issue of the Private Pilot Licence (Aeroplane) or those parts of integrated courses at Private Pilot Licence (Aeroplane) level and class and type ratings for single-engine aeroplanes, excluding approval of first solo flights by day or by night and first solo cross country flights by day or by night;
and
(b) night flying instruction.