I break all the rules. I ride in whatever bit I feel like on a given day. Snaffles, curbs, tom thumbs, mechanical hackamores. I even direct rein in them. Gaited horse folks direct rein in curbs all the time. I have never noticed a difference quite honestly from something like a Myler with the swiveling mouthpieces and a basic curb with no moving parts. Now I love my Myler bits (I have 3) but I also ride in normal curbs and my horses ride nearly the same no matter what bit I use.
The only bit I feel gives me less control is the snaffle, but hey, they ride great in that too. I just get less breaking at the poll in a snaffle, and if we go for a canter it can be hard to slow them up. But basically, I switch up all the time and the horses know me and ride the same for me no matter what I use.
I personally have had good luck with the tom thumb, much to the annoyance of everyone on the internet!