So we bought a 2020 Sienna in August. One of my conditions was being able to transport 4’x8’ sheets of whatever plywood, drywall or whatever and was assured that I could. So after purchase I folded down the rear seats and removed the middle two, very easy btw, and to my surprise the raised track holding the middle seats is not removable and whatever is loaded will rest on it. I loaded ten sheets of 19/32 CDX plywood with no problems but I felt uncomfortable. Is there a load bearing weight limit or should I build a ramp to place over it for future loads?