Upgrading EV 9 to EV 11. Do I need to go to 10?

I am upgrading EV9 to EV11.  From what I have seen I need to upgrade to EV 10.

So migrate to EV 10

Then upgrade to EV 11.

What about the clients?  I have outlook 2010 clients.  Do I upgrade addins to 11 before I migrate?  Or upgrade then to 10.

Thanks