Yes!!! Only I would argue there's no need to mention the survey at all. They can ask, "If you feel my service was anything less than excellent, please let me know so I can make it right." or something like that. If
DCL truly wants honest feedback to improve upon, the survey procedures they currently use are not productive. The fact they have a question asking if you felt pressured to give an excellent rating shows that this is an obvious potential problem. I love the WDW surveys that come after a stay at the parks where you can take them with no pressure and you have plenty of space to leave extra notes.
@PrincessShmoo, I love your idea about taking extra paper along to leave extra notes for the survey! I'll be doing that next time. There are so many times I had a CM go above and beyond but there's just not enough room to include everything.