To OP: If you're interested in more hard sci-fi technology, I'd take a look at Terra Invicta for some inspiration. The technologies are more on the hard sci-fi side with a handful exception (Exotics being the magical alien material that helps some of the plotlines to work and gives them a technological advantage throughout the game), so it could give some ideas of potential technologies rooted in reality. The game itself is hard and time consuming, but pretty fun if you can get the hang of it.
FWIW, that is
exactly what I was thinking about, the moment I realized what the OP meant.
Interestingly enough, for all that BT is extremely "backwards" where things like maximum (or even just effective) weapons ranges are concerned, even the aliens in Terra Invicta would probably sell their favorite grandmother in order to get their hands on BT drive technology. I mean, sustained thrust at 1g or above even for million ton battleships, and 24.000-ish kps (assuming four weeks of thrust at 1g) delta-v - that is a
wee bit better than the best I´ve seen their ships sport.