Mark, my experience on the assist rigged single off the head is very different from yours. Part of the very exhaustive testing I did with every model of the Kongs from Fullscale was to test them with the hook configurations which we see used locally here which is trebles, single and baker, treble and single, assist and single and assist on its own.
I don't use the assist rigged single off the head because I don't like its impact on the action on the lure. I have since tested the same on a prototype of the Sea Frog and the SF dislikes this rig even more. When we test a lure properly, it means we test them in all sorts of ways - different hooks configurations, different conditions and even different types of boats. Fishing off the front of a gameboat is very different from fishing off the front of a small dory in terms of height. The lure has to perform at all levels before it passes the necessary tests.
My experience is that the old model SF with the blade off the tail swam like a dog with the assist rigged single.
What I have found is that the bigger poppers are more able to handle the assist rigged single off the head and in relatively calm conditions, you don't notice much difference but if you are using it in heavy conditions, it becomes quite noticeable. The reason for this is very simple - there is not one GT lure manufacturer that I know of that tests its lures to carry an assist rig.
I did have one member arguing strenuously a while back that he could rig stickbaits with an assist off the head and it swam just as well as with trebles
It is hardly sensible for an angler to have to compromise their rig because of inadequate terminals being used on a lure but it is good to see that Heru has finally been "persuaded" to upgrade its terminals.
If you are concerned about the belly swivel on any chugger, hang a single assist off the towing point. It will have no effect on the action of a chugger.
