You mean other than the fact that there's a couple of orders of magnitude difference between what their FBP reflects at me vs what a full-sci, max-rank, max-aux FBP will reflect back at them, right? Or how about the fact that FBP only works against energy weapons. Not torps. Not exotic. And there is nothing like FBP for…
It's not listed anywhere, but Nimbus and other quest line listed under the Available tab only unlock after you fully complete all storylines prior to Romulan Mystery. For Federation captains, this means all of Klingon War, up to and including The Galaxy At Large.