Field Parameters in Matrix visual: Maintain current expanded/collapsed context view between parameters

Love field parameters. Amazing. Game changing.

I have a matrix with product groups & the individual products beneath them (I use a matrix because there are hundreds of products within about a dozen product groups).

My default value to show is Expense by product, but I often want to switch to see how many orders of that same product I've ordered.

Field parameters seem like a wonderful solution. However, when I select my "Orders" field parameter, the matrix is essentially reset. I had expanded one product group when viewing Expense, but when I switch to Orders, all product groups are expanded - displaying hundreds of products and I've completely lost my place.

Also, I typically sort Descending on Total Expense or Total Orders, but when I switch back and forth between the two it does not store my previous sort behavior. If there were a way to set and store the sort logic for each parameter that would take this 99.9% useful feature to 100% for me.

Thank you!!