The only thing I can suggest is defining a Battle zone, Because although the fight will stay in Eta, but still, Ships camping the Jumpholes where the hostile ships come from can raise some issues (Like it did in the last event). So, What I suggest is restricting the fight to an area like This. No Outcasts going past Lentini to Camp Theta Jumphole, and No Corsairs going past Siracusa to Camp Alpha Jumphole.
So, if one side manages to kill every ship from the other side (And considering it'll take the newly respawned ships a few mins to get back to Eta) They'll just sit there - or go back to resupply - until the new wave of enemy ships arrive, instead of camping the jumpholes to pew pew every single ship that jumps in.