What does the front bit of your MEL/DDG say?
Ours says the following:
"It is within the authority of the Commander to accept a defect without consulting a ground engineer after the doors are closed provided the defect does not require a maintenance (M) specific procedure and it is covered in the MEL."
But it also goes on to say:
"No flight shall take place with any item of aircraft equipment inoperative or outside the requirements of the Operations Manual, if in the opinion of the Commander the lack of such equipment or the relaxing of an Operations Manual requirement will jeopardize the safe conduct of the flight.
The decision of the Commander to have allowable inoperative items corrected prior to flight will take precedence over the provisions contained in the DDG. The Commander may request requirements above the DDG, whenever in his judgement such added equipment is essential to the safety of a particular flight under the conditions prevailing at the time."
So, while it's not necessary to return to the gate unless the defect requires a maintenance procedure, the Commander still has the option to do so if he or she considers the equipment to be essential to the safety of the flight.