I booked the Marhaba lounge once for my elderly parents. They travel through DBX twice a year and had a 5 hour layover that time. They didn't think it was worth the money (that I paid!) and prefer to buy their own food and sit close to the gate they are departing from. This was a few years ago so there may be more lounges closer to your departure gate. I think there was a set 3 hour maximum time as well.