Due to the immese amount of damage focus fire causes, even with shield mitigation, repair abilities are useless. Your ships will be destroyed before they can be repaired. Use the crippling abilities. These work.
Repair abilities might work before heavy cruisers, but scuttle all repair bays and turn off that repair auto-cast after that. Make sure to research crippling abilities instead. Focus fire is stupid, but it is how the late game works.
You might be able to save a cap ship with them, but I doubt it. You might score yourself an extra attack. Who knows? I still don't think the repair abilities are worth it. Designate targets and use those crippling droids.
Any thoughts? I would really rather I could effectively heal. I like the idea of saving ships.