Would it really kill your cruise engines when you run out? That would make what I had in mind unfeasible... since then you'd either have to have a low drain so you could get places (doesn't hinder cruise->reengage, so useless) or a high drain (forces you to make several hops across a system.)
If engaging cruise zeros your <<<<WEAPON ENERGY>>>> but does not at any point take you out of cruise, I still think it's a good idea.
