With accordians instead of boxed fieldset, the last custom fieldset on the open case form has no "end"

In 3.1, custom data fieldsets were surrounded by a box, so it was obvious to users where the non-custom case fields that they need to fill out at the bottom start.

But in 3.2, especially if the custom fieldset is optional data rarely filled in, the bottom fields look like they are part of the optional data. For people upgrading from 3.1 it's not an issue since they are already familiar. For new users it would be useful for the accordian section to have a visually defined "end".