We do not talk about midichlorians
Jokes aside, if you want something that can be big but that can not really alter the "game plan" even in the long term, there are a number of things that come to mind.
The first that does is intersystem migration in outer space. We know from V that there are giant worms and stuff living in asteroids. Are those creatures trying to go anywhere, or just let themselves be carried with the drift? With orbital periods (if any) approaching the tens of years, what do they even do in their spare time? How do they find potential mates? Do they have a concept of territory?
Another potential one -touching weapons and shields but not affecting their game plan- could be how to improve their storage requirements, in particular when not in use. Are the laser guns and shields stored for long-term trips with their "batteries" on? Would that be potentially detrimental to their effectiveness? You could even throw in a jab in the form of eg.: the studied methods scaling so badly that "you'd need a planet's worth of thermal oscillators to make a decent laser out of them".
Of course, stellar mapping is also a thign that could be done in the background, since during the era of Sidious enough information about the galaxy's structure was lost that by the time of VII apparently only one, still fragmented, map of the full galaxy remained.
