The SEXP jump system I have set up at the moment distinguishes between an attack-jump and a retreat-jump, based on whether or not you are facing a target. Unfortunately, because of the way FRED handles things, I have to make a list of combat-warp-attackable targets for every mission, usually capships.
An attack jump teleports you in the direction you are facing, to the distance to target, minus 2000 meters. It's great for rapidly closing the distance & making things dead, and also great for escort missions when you need to get back to your escort targets.
The retreat jump just teleports you 7500 meters in the direction you are facing, if you try and jump when the attack jump criteria are not met.
Currently the subspace jumps are hooked to a timer. After executing one, a ship can't use any of its other abilities until it's recharged. Depending on how flexible this new ability system is, I wonder if it's possible to set up an ability energy bar, and have stuff begin malfunctioning severely if it falls below zero.
In the campaign I'm designing, the Shivans are masters of quantum ****ery. If they need to extract 40 units of energy from a bucket that only has 30, they will find a way to artificially induce it by screwing with the fabric of space-time. Energy reserves 'going negative' for short periods of time are not that unusual.