I asked Google "how to convert a manual rv awning to electric" and it suggests to replace the roller with a motorized roller, or replace the arms with motorized arms. My 2010 has a dometic awning (of the same year) with the motorized arms and no problems with it.... So far. My thoughts are that a same brand conversion would reduce the chance of additional/new holes in the side of the coach for the arms... You would only add a hole at the top front(right) end for the new wires to control it.
I think it is worth contacting Dometic to see what they suggest. I would think the answer is going to depend upon the model and year of your existing awning, so have a picture of it as well as any stickers/numbers/labels included in the request.
I wish I could offer more, but I've never encountered idea this before.
Larry