Baby is due in 3 weeks and I have kindly been given a friends xplory with carry cot to use. However I'm not sure if this is a stupid question but could someone tell me if I need a harness if I'm using the carry cot? I've seen a stokke harness that can be used with the tripp trapp chair and the stokke carry cot but I just wondered if it was essential? Sorry for my lack on knowledge - first baby and don't have a clue!