I kind of agree with Innovate1's original response. If it was me, I'd want a control system to reduce both the pump run time and the heat loss from the loop.
If you're in a cold weather climate, I guess you could consider the heat loss a wash, because that loss is just going into the heated space anyway. But if you are running AC, then you're doubling up on your loss, because your loop loses heat to the building envelope, then you have to reject that heat to the exterior using your air conditioner.
Regardless of if was a pushbutton, smart switch, timer, whatever....a control system of some sort so the recirc system shuts down when not needed would be a huge plus.