I don't have a Newmar but I did add the two friction hinges to our LCI door. They work well. Where the door used to blow halfway shut and then slam open before, the door just sits there now. In Florida winter the winds used to push the door often and now they do not.
We kept the pneumatic strut on the door so it cannot get in the way of an awning arm but it's not needed for the door itself.
Some RVs come with the friction hinges and many people have reported bent door frames. I don't know if that's because of flimsier construction in trailers or because of too many friction hinges.
Adding just two has not affected the door or frame at all, yet...
And yes, if "someone" just let's the door slam open without holding it, that problem goes away.
FWIW,
Ray