I have a similar issue I've been thinking about, where I'm sending lots of data from page to page.
One possible solution would be to use nsv_arrays. It's kind of a weird way to do things, I guess, but in my case (where I'm not using ad_form, and I actually am sending a lot of arrays between pages), it might make sense.
Someone mentioned internal redirects, but I'm not really sure how those work.
