subpanels: Save Collapsed or Expanded Status

By setting hide_subpanels to false they are always expanded. How can I make it so that SuiteCRM saves whether or not the panel is expanded or collapsed?

It seems the new Theme has removed this feature! A shame. Hope you guys (salesagility) add this in soon. That way you can find the sweet spot between best performance and usability, by just displaying the most relevant subpanels upon page load.