@ findeight.
FWIW, it wasn’t the OP who believed that the horse needed more consistent contact in a bosal. I believe it was an FEI judge who said so in comments.
And the pot-stirrer that I am, I can’t help but point out that perhaps an FEI judge doesn’t know jack about how bridle horse training works.
OP, what F8 did say that was right and worth re-reading is the bit about a horse being able to bull through a bosal, riders rubbing the skin off and really, really trashing a horse once you teach him this very “wrong” way to relate to a bosal.
As others have described on other terms, the bosal works on a “signal” or a contrast between when the facial nerves long the horse’s nose are touched and when that touch is released. Holding on too long is the kiss of death; there’s not contrast there, just suffering and no horse will stay sane and trying for too long in that situation.
What the FEI judge might have wanted (and which I’d want too… and I think a top WD person would want, as well as a Bridle Horse Person (I think) is a horse who is what the Dressagists call “through.” That is so say, he is using his whole body. He’s pushing from behind and allowing that energy to flow up to the bit via a relaxed topline and engaged core.
The way Western Disciplines tend to get that (and the type of horse that populates their tradition) and the way Dressagists get that (and their very different horses) can get folks tangled up.
I mention all this mainly because I think you might be getting caught between 'em. IMO, getting a horse who is “Western Light” in the bridle to carry himself and be “through” all.the.time is much harder than it is when you have the consistent contact of the Dressagist. Really, it takes a ton of feel and skill from the rider to produce a horse who responds to the bit (or whatever he’s wearing on his head) as a signal device But! also uses his body to push forward into that. And note: The horse isn’t pushing into contact. This is a little bit theoretical, but I think he’s pushing forward into an uphill posture with a relaxed topline. The “wall in front” is a signal in front that he knows about.