Bottom line is that the automatic Zip-Dee awnings simply don't tilt very much. I have a 30' and it has a hard time shedding water. The old mechanical ones tilted much more.
Its a design thing, you cannot get them to tilt more than a few degrees - its due to a limitation of the software on the control board. Your dealer nor airstream will be able to do anything about it.
On a 25' it's not as big of a deal because the distance is shorted and as a result they get more degrees of tilt - but on a 33' I would not leave the canopy open during the rain. This is what airstream's official stance is on the matter (it is a sun share, not designed to be used in the rain).