Good tip, if there is a concierge lounge on your ship, let the suite concierge do the work for you. That is what they are there for. Of course, I suspect that you'll get better and more complete features in the app as your sailing gets closer.
Everything depends on the sailing, but last time we took advantage of the complimentary specialty dining on embarkation evening we found that the Crown Grill (in our case) was nearly dead. We did call the dine line after we got on board to secure a reservation for our party, as it was 5 people, but once we got there we discovered that we could probably have just shown up and been seated. It was not busy at all.
The complimentary specialty dining is a nice suite perk, however the reason it is only provided on the first night is also functional for the cruise line. First, it is my impression that specialty restaurants are not heavily used on the first night, again varies by sailing, and it also helps to get some passengers out of the MDR. What better way to spread your pax out than to encourage your suite passengers to have specialty dining embarkation evening and get them out of the MDR flow, get some usage out of the specialty restaurants which will may be underutilized that night.