I don't have a DP, but the mechanics is the same. Here's a photo of our TT with the television in the UP position. I'm assuming, this is something similar to what your looking at. (Assuming this is what your taking about, more comments below the photo):
The lifting mechanism on (my) television does so by 1 long screw turned by the motor at the bottom. The lifting mechanism raises and lowers as the screw turns, like an auger. You can see the motor and the long screw here:
Here's a view of the mechanism with the television in the up position. The camera is looking straight down.
And here's the same view with the television in the down position.
With the top on the cabinet, down and up:
As far as traveling, we always leave the television in the down position. I think in a motor home, you'd want to do the same.
I have to admit, I've never ridden in the camper when in motion, so I don't know how much noise it makes, rattling, or anything. But I do know, the lifting mechanism is solid. The only noise we hear is the motor running when lifting or closing. There no shake or movement in the up position. It really is pretty solid.
I don't think you have anything to worry about, even if it did get stuck in an up position or mid way up. Although it takes a little effort, it can be lowered manually, or the television can be removed completely.
Good luck, and have no "fear! if this is your only concern about your new "impending" purchase!