For kilning, the packing density doesn't matter, so long as the leaf is maintained at an adequate humidity, and above 120°F (to prevent mold growth). I have kilned leaf hanging on strings, leaf pressed into dense pads, and large quantities of leaf simply dumped into suitable plastic bags (that remain open). All of those worked well. It's about temp and humidity.
On the other hand, if you intend to use the same chamber for flu-curing, then the leaf must be hung or suspended in such a way that air can easily circulate between the leaves, otherwise you get uneven flu-curing. For flue-curing in my chamber, all of my leaf is hung on string--actually wire, and a fan maintains circulation.
Bob