Faster than Vmca means that you'll have a lot more drag to overcome from the failed engine as you feather it, and it may be difficult to maintain directional control as you slow down to Vmca.
Eh? Vyse is above Vmca. Why would you be slowing down to Vmca? In terms of directional control, the extra drag of being faster than Vmca is more than offset by the extra rudder effectiveness. Kind of fundamental to know. More speed = more directional control. After clearing obstructions you fly Vy, if you lose a donk you slow to blue line speed - unless you are intending to do a low level Vmca demo.