The manual states that on the bottom right are a series of characters:

SCOC█

That correspond to shift, control, option, command, capslock.

So those looked like interesting things to figure out some more scan code for the non-printable keys.

I started with capslock since I have found the flag indicating it's state.  I found a snippet:

F3C6             loc_F3C6:
F3C6 13 A1 01 0A     brclr   bCapsLock_A1 1 leave_F3D4 ; flag; CAPS lock in effect
F3CA C6 9F           ldab    #159            ; cursor at end of screen
F3CC BD F7 60        jsr     commonSetCursorPosB_F760 ; common set cursor position (abs pos in B)
F3CF C6 0F           ldab    #$F             ; solid block char
F3D1 BD F6 74        jsr     sendLCDbyteB_F674 ; send byte in B to LCD (w/ctrl as per 0x5b)
F3D4             leave_F3D4:
F3D4 39              rts

Straightforward, but no SCOC in sight.  I am inclined to conclude again that the manual is for a later version of this product than this v2.03 firmware.  So I won't be able to discern those scan codes yet.

This snippet is still interesting, though, because it's part of a function that does other displaying stuff and accessing file contents.  So that routine sub_F374 might be the 'display current file' routine.