This is a chain practice that has always puzzled me. I can't see how pre-packaging popcorn, then expecting you to put on your own topping does anything but save THEM time. No matter how you do it, you can't get the topping below halfway... well, maybe if you saturate the top. You wind up having to leave the show to get more topping. Oh, wait... there it is... an opportunity for the theatre to sell you MORE STUFF! How could I have missed that!
We have always layered our medium and large tubs... which is the main reason I've stayed with tubs... easy to handle from the bottom. The customers love it that way, and the process of doing up their order makes them feel like we've put a little time into their purchase.
I know this doesn't answer your question, Noboss... sorry. Move to Washington!