Multi-Screen (3) setup and management

Assuming I’m right about XFCE,
What risk is there to change the DE in Dom0 (to Gnome which I don’t like of to KDE which I’m found of since Mandrake and the Suse)
I see in this post that KDE seems to be a candidate and the “right” choice ?
Or should I just wait, using only 2 screens, for the next rev’up onboarding KDE ?