He may have set features at work (6)
I believe the answer is:
editor
'he may have set features at work' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'he' is the wordplay.
I cannot quite see how this works, but
'he' could be 'ed' (short for Edward) and 'ed' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for editor that I've seen before include "Person responsible for publication;" , "Redo it and become head of publication" , "One who determines the final content of a text" , "cutter?" , "Person who determines the final content of a text" .)