Interesting set up.
So you have an interesting race potential set up. The Jovian Republic is likely to get a major jump on extra-solar exploration. A lot depends on how confrontational it gets about protecting its claims, and how secretive it is about which warp points are the ones it is sending colonization efforts through.
So long term, the Jovians have a potential advantage in growth and resource access. However, short term things are uglier for them.
In Starfire, projections of future economic prospect were a bit more reliable, but in Aurora it depends on a lot of unknowns. There could be a political faction in the UNE which discounts the likelihood or proximity of habitable worlds with significant resources.
And there could be factions in the Jovian Republic which might believe the best chance is to scorch Earth's population and economy as soon as a viable extra-solar colony is established.