Western Riding; Should a horse move on to a curb/shank bit once it is well-broke in a ring snaffle?

I don't think buckaroo has much to do with this at all, since I sell quite a bit of tack to the buckaroo people and they do not all ride with snaffles. Most will graduate their horses up to a curb bit so they can add the romal reins and rein chains along with the super fancy curb bit. Buckaroo is way more if a mode of dress than a way of riding. I think it is more of the "new trend" that has people in a mind set that a snaffle is the gentlest bit, so they stay with it. Kinda like leaving your teenager in kindergarten. It is easy on them, but they are not advancing much in their education. I think horses should be "graduated" into a shank bit. As long as the hands holding them have some education, most shank bits are not that severe. How tight the curb chain is detemines more than anything how severe the bit is. I do swtich back and forth from a curb to a snaffle, if one of my horses needs a bit if fine tuning or is getting a little stiff on his flexing, but all of mine by the time they reach age 4 have been put into a curb bit. While I know it is tempting to tell her she needs to switch him over (and I agree in this), it is also her horse and so she has the final say in what she rides him in. And if she likes this bit and this "look", then let her do it. Telling some people how to train their horses is sometimes like telling them how to raise their kids. It is just better not to say anything at all. Unless they ask you. And then you still have to be careful how and what you say to them.