Call me lazy, but I use the designer as an ad-hoc reference tool.
While moving AutoScroll = true from a form into a contained panel (the purpose being to add a status panel at the bottom), I found that the panel won't scroll with the wheel any more, so I've got to do it by hand.But I had to dig around to find the MouseWheel event, because it's not exposed to the designer.
Followup: Rather than do it by hand, just calling the subpanel's OnMouseWheel solved the problem. It meant I had to inherit the Panel class, and expose a function to do the bubbling, but as I'd already had the panel subclassed, it was 3 lines of additional code instead of trying to figure it out on my own.