So I’d like to explain to you what the point of using both would be:
My mare was pushed too hard as a 5/6 year old and when the breeder/owner found out what the trainer was doing they immediately stopped her training but she still learned a LOT of avoidance techniques.
So when I ride on the flat she holds herself in a “fake” frame (what tends to be from the over use of draw reins) and she’ll go behind the bit to avoid contact. Now we spend a lot of time working on this but her tendency will ALWAYS be to go behind the bit.
Now when I jump her in the ring a loose ring French link generally does the trick but there are times where I pull harder than I would like to on her sensitive mouth to get her to stop.
And then when I take her out on trail rides with small jumps for “confidence building” she is impossible to stop after jumps in the French link.
So I spent a lot of time looking for a bit that would get the desired result without causing her to curl more (as elevators and hackamores are known to cause curling). So I found the gag. So I hurried off and bought myself a loose ring snaffle gag (with normal not big rings) and gave it a try.
So I put two reins on it, to make sure I was using it correctly and off we went. And for real, off we went! But this time instead of avoiding the bit with curling she was resisting the bit by flipping her head almost straight up.
So I was a bit at a loss. But I figured I’d go ahead and try a loose running martingale before I completely gave up on the gag. Of course it seemed counterproductive to myself as well but it works. No head flipping, no curling, maybe it’s because it lessens the effect of the gag action while keeping her head down but not allowing her to curl.
So basically, it keeps her from using avoidance tactics to blow off my rein aids.