In fairness, if you think you know more than your farrier, you probably need a new farrier. I’m not saying that you don’t know more than the farrier, but if you find yourself in that boat either 1) you really do know more than the farrier which means your farrier sucks and you need a new one. Or 2) you don’t know more but have such little trust in their skills that you feel you need to correct them. In either situation, it’s not a good fit. Same thing with trainers, or vets, or doctors, or lawyers or any other skilled profession.
That’s not to say I don’t discuss things with my farrier. For example if my horse is forging I’m definitely going to tell them about it for next time so he has all the info he needs to fix the problem.