Right. Your casing container of choice will be well above 75% RH.
@webmost has
this video showing his method for casing wrapper.
Not so different from what I do. I use a tub, spraying the sides and inside the top through the process to keep the humidity up.
First when I get the pound, I'll roughly separate the leaf, spraying the leaf, with my hands I'm spreading out the water on the leaf so it doesn't pool so much.
Throughout the process I'm separating the leaf into individual leaves, stretching out the folds and crinkled bits, sorting them into likened types and stacking into one pile from light to heavy.
And yes, beyond the point of storage case, beyond the point of assembly case. The case level is for stretching out the leaf, and further fermenting the leaf. Not a very safe place to be for long. It will deteriorate to dust if left.
In the middle of it all the leaves have been dried to the point to where I feel comfortable enough to put it in a bag. This will take as much time as it takes. It does move along at a point so it will get a little attentive.
I will also revisit prepped leaf in storage, opened bags to check and adjust as necessary. A common practice of mine. More often on leaf that may need further drying that has just been sorted for storage.
It lends to pre-assembly preparation. Prep for assembly for bunching lends to bunching efficiency.