Also do the fruit roll sheets and clean a screens add to drying time. Making jerky and don't want a big mess.
I've used 6 trays for jerky,but can't tell you if drying time is any longer because every load is different due to the moisture content of that particular batch. Can tell you that I still don't have to rotate the trays for even drying, even with 6. Never used any screens because the plastic trays clean pretty easily.