AutoTarget.cs

// existing code
Actor ChooseTarget(Actor self, WRange range)
{
	nextScanTime = self.World.SharedRandom.Next(info.MinimumScanTimeInterval, info.MaximumScanTimeInterval);
	var inRange = self.World.FindActorsInCircle(self.CenterPosition, range);

	return inRange
		.Where(a =>
			a.AppearsHostileTo(self) &&
			!a.HasTrait<AutoTargetIgnore>() &&
			attack.HasAnyValidWeapons(Target.FromActor(a)) &&
			self.Owner.Shroud.IsTargetable(a))
		.ClosestTo(self);
}

// new code
Actor ChooseTarget(Actor self, WRange range)
{
	nextScanTime = self.World.SharedRandom.Next(info.MinimumScanTimeInterval, info.MaximumScanTimeInterval);
	var inRange = self.World.FindActorsInCircle(self.CenterPosition, range)
		.Where(a =>
			!a.HasTrait<AutoTargetIgnore>() &&
			attack.HasAnyValidWeapons(Target.FromActor(a)) &&
			self.Owner.Shroud.IsTargetable(a)
		);

	var healer = attack.Armaments.Any(arm => arm.Weapon.Warheads.Any(w => w.Damage < 0));
	if (healer)
		return inRange.Where(a => a.AppearsFriendlyTo(self)).ClosestTo(self);

	return inRange.Where(a => a.AppearsHostileTo(self)).ClosestTo(self);
}