I use Illustrator on my laptop screen and also when plugged into an external monitor.
When switching between these screens I often have to adjust which panels are collapsed, and the size of each panel, particularly when going from the smaller laptop screen to the external monitor.

It would be very helpful if the workspace settings could remember not just which UI panels you have open, but their size and collapsed state. This way I could have a preference for when Illustrator is displaying on a 15" laptop and one for my 27" monitor.