I suggest that there is an option button to "Hide" the mount that is currently equipped.
In other words, your regular wizard avatar would have the speed boost - and perhaps even the minor stat boost - of the mount but it wouldn't be accompanied by a mount that sometime takes up a large portion of my screen.
I know this is nit-picking, but i have a gulture mount and the darn thing 'seems' to always get pulled into fights, or sometimes it takes up so much of the screen that i cant see where I'm heading and...WHAM...instant fight.
This is just a suggestion. Thanks for listening. Have a good day.