This would be the first I have heard that about the mixing tubs.... but I am in my racks enough to notice chewing to be honest, at the min I am looking over everything twice a day and every few hours when I know litters are dropping....
as for the dish tubs i know people have talked about chew outs cause of how flimsy they are so we shall see how that goes....
and man man I wish I could get that rack, that one is on point lo maybe one day