It's getting late in the Mackeral season up here (Palm Islands) so it's late to be thinking of rig changes!
Anyway, I don't bother with bait for Mackeral, I use Halco lures 2+ & 6+ meters and get a good strike rate. I have only had bust offs when I've had a swivel attaching the leader to the line - as they seem to go for them. I use an albright to attach 3 meters of 80lb mono to 30lb or 50lb braid.
If I'm going to loose a Spanyard it's when I'm trying to get it over the side of the boat with a couple of excited crew with gaffs and nets hanging around getting in the way!