Well, I have a different slant on the Resrve dining. We have the same problem as the OP where we have Reserve and our traveling partners do not. When we originally booked we were "standard" dining but our TA notified us that we could get Reserve and end up actually paying less than what our original fare would be in a standard mini-suite. Of course we jumped on it! Then, our friends booked but Reserve was fully booked up.
Now, we *were* going to take advantage of Reserve (of course) but now that our friends are involved we prefer to eat with them. (We might take 2 or 3 meals in Reserve...)
The issue that I have is that I cannot book any non-Reserve dining for all of us except for SD. When I try to do so it only shows us specialty dining since the system "knows" that we are Reserve!
I realize this is not going to be a common issue for most! We have done this once before when it was known as Club Class. We only did the upgrade primarily because of the overall savings we were going to get.
I am posting just to point this out with the DMW app. Our friends ended up having to book all of our dining since we could not. Again, not a big deal...it's just that I am usually the one who handles all of the details like this for our group. Just FYI...