I’d own a chambon before any other lunging device, including the much-venerated side reins that are part of the standard dressagist’s repertoire.
The chambon works well for the mechanical reason you state. By my way of thinking, I actually only want to control the base of the neck and, if I could, I’d ride even the young, weak horse so that he lifted the base but left his nose sticking out. For this reason, I don’t love it that taking contact usually gets a horse to tuck his nose first and raise the base of his neck (with some added stuff like impulsion), second. If I’m a skilled rider, of course, I can finesse all this to get the posture I want. But a fixed device? Usually, the horse will curl behind the pressure in his mouth before he’ll raise the base of his neck and withers. I think the chambon is simple, correct and “generous”-- it only puts pressure on his mouth (and then, on the corners of his lips, not the bars) if he inverts or raises his poll badly as in having his neck “upside down.”
A few more caveats:
Lunging in equipment can get you only so far. It takes a good eye and diligence to get the horse to move up enough into the device that he actually uses the rest of his body correctly. If he’s “behind the leg” so to speak, you are wasting your time, his legs and just creating a head set.
I also think a chambon encourages “long and low” and, IMO, dressage riders can over-do that. Yes, a horse should be able to take all of the rein you feed him. But that’s just a skill to have, not one to drill, really.
For horses with a screwed-up relationship with the bit, however, taking a rider out of the equation and putting in a simple, predictable device works really well.
Buying a chambon can be tricky. Some of them come in wacky-large dimensions… so large that you can’t punch enough holes in the leather to make it fit even a regular-sized horse.
ETA: Personally, I would not try to teach my horse any relationship with the bit or any particular position for his head until he had W/T/C, steering and whoa in tack. I think dressagists put way more emphasis on how the horse feels in their hand than they ought to… especially when that “consistent contact” becomes a horse who is also behind the leg because he’s not actually strong enough to push from his hind feet all the way up into the bridle the way we want… so he just stretches down and we call it good, not really feeling that he lacks impulsion.
Also, baby horse will need to put his head and neck in all sorts of places while he’s using them to balance his young, top-heavy body and then a rider even higher than his own center of gravity. So his relationship with the bit at this point in his education is pretty dang minimal. Or, if you watch the really great young horse riders, the head and neck isn’t a big part of the equation. I suppose the very talented, athletic Verdan auction riders can finesse a young horse’s head and neck so well that he looks like he’s got more strength and miles under saddle than he does.
And I try not to spend lots of time on a circle with the babies, especially the tall, heavier, leggier ones. If those legs will get used up during his career, I really don’t want to spend them on a circle before I even get to ride him, lol!
Hope this helps. Take what you like and leave the rest.