I don't know what that space is, but we sailed in 524 on the Riviera deck, Royal Princess, a number of years ago and according to deck plans it has that same open area. We never heard a thing.
I personally would not be offended in the slightest if my cabin mate said he was getting military OBC and was using it for any reason. This Canadian thanks you for your service.
You're likely aware of this board already, but Cruise Fashions and Beauty has lots of interesting (to me, anyway) threads. They're not Princess-specific but I find them informative.
https://www.amazon.ca/dp/B07V2N2YKC?slotNum=4&ots=1&ascsubtag=[]c2[p]cj1i2m57500a7y5yeie4ql0qo[i]zRjnsp[u]2[t]w[r]lens.google.com[d]D[z]m&linkCode=gs2&imprToken=62c0aecb-8a88-ed17-6a2&tag=voxcan-20&th=1
I found it! I've been on a mission to find it lol.
I feel either of the black pairs you posted would be absolutely fine in any dining room. The black sandals on the far right are probably the dressiest, but whatever you prefer.