>> After cleaning, the seeds are usually placed on a paper tray about 3"x3" made from newspaper, with sides 1/4-1/2" deep, and those are placed on cookie trays in kitchen cabinets that used to hold dishes.
That sounds like a great way to dry seeds or seed heads that are too wet to go into paper envelopes (if you have enough cupboard space).
When I try to dry them in a paper envelope, I either use multiple envelopes so no one of them has a DEEP layer of drying seeds, or shake them several times per day.
Soggy seed heads I press between coffee filters and cotton towels. Then I keep them separate from other seeds until they are very dry and I'm pretty sure they won't go moldy.
But I can't figure out any way to keep from losing things and then finding them years later. When totally dry and in "The Stash", I can find them.
But every place I think of to put things "where they won't get lost" ... they get lost there.