Small loan fight? 
Possible solution: EVE strategic “chess” game. Each ship entering battle is added as a “chess” piece. After a previously announced and set preparations time window the system is locked down of ships entering. Then the two FCs start taking turns, controlling the chess board, playing a turn based game where there is no time dilation and only strategic level actions and thus calculations are performed. The battle ends when one FC decides to retreat (as an attacker this can be after the keepstar is destroyed or sooner, as the defender before the attackers are eliminated or after).
May this be completely imbalanced and absolutely not representing what would have happened if the battle took place in real time on grid, at least someone could win, there would be no lag and wouldn’t take ages with no satisfactory end result… I think still a better result however unrealistic this may be than what we’ve got.
Well just a random idea but thought I share it anyway maybe it can evolve to something more refined. Partly a joke but partly could be turned into something good so two reasons already to put it here.