Sarawak plates used to follow divisions, example if division 6 the plates would be 6D####... So I think it's possible that 1/2/3/4/5D/DA also exist. Haven't seen any of those though... And never even HEARD about those.
J #### S is an old Kota Kinabalu plate, when it was still Jesselton. It was after EJ, but before SAA #### A. They changed like this: EJ #### → J #### → J #### S → SA #### A → SAA #### A.
E was for the state of Sabah before S. The oldest Sabah plates.
EJ - Jesselton
ES - Sandakan
ET - Tawau
ED - Lahad Datu
EU - Keningau
EK - Kudat
EL - Labuan
EJA is actually from the 'EJ' series - when they reached EJ 9999, they started EJA 1, etc. Same goes for all the others (ET/ETA, etc).
D #### S was Lahad Datu after ED; T #### S was Tawau after ET (similar to the evolution of EJ plate explained above).
SG #### - Sabah Government
SL #### - Labuan when it wasn't part of federal territory (after EL #### but before L ####).
Sarawak plates were:
1/2/3/4/5D/DA - existent or not???
6D####, 6DA####, 6DA####Q - Sarikei
7D####Q - Kapit
K####, K####Q - Kuching
S####, S####Q - Sibu
M####Q - Miri
J####Q - no idea where it's from, but it exists. Saw J1Q on a yellow Ferrari.
They only started adding 'Q' postfix in 80's (as far as I know, LATE 80's).