The real trick to make a door operate smoothly is to have it sit in the tracks in such a way that the force required to pull it up doesn't change much from closed to fully open. In a regular setup, the door is essentially balanced by the springs when the door is closed. As the door rises, the upper part of the door curves around and sits on the upper track relieving some of the lifted weight. At the sime time, the spring is unwinding(in the case of a torsion spring) or getting less extended(as in the case of an extension spring) and less force is applied to the door. The two working together make the force required to lift the door almost equal throughout the travel. This works well for the safety mechanisms in the door lift because they are set according to the force-- a large increase in force going downwards signifies the door is blocked because something is under it.
So, while it may work with the track modified to follow the trusses, it may be difficult to adjust the safety mechanisms unless you can adjust the springs to balance the weight differently or you will get false trips.
