Other keyboards on bigger systems at the time had function keys (most notably the original IBM PC of course).
Yes, but on another system the fkeys have a fixed control code, which can be detected by user softwares.
On the Enterprise the fkeys (in normal and Shifted mode) can be defined by the user, for simulating pressing any other keys.
For example type START and pressing the Enter.
Nowadays this function is called Keyboard Macros.
I think this is unique at the Enterprise time.
I wrote a utility for Function Keys, it can record key pressing for the definition, and is able to save and load Function Key settings. It can be used in any software which uses EXOS Keyboard device and can run EXOS commands.
For example I used it in Assembler, the most used subroutine calls definition to Function keys.