I vote no in general BUT…!!!
I absolutely agree with what ya"ll have said but…I think a LOT of dressage riders are not well educated about the horse handling himself thing or thinking for himself. I see a lot of bad dressage around here that I can’t see how it would help a potential or current fieldhunter. Schooling, training, self carriage, responsive to the leg etc is all good stuff. But I don’t think the endless schooling in circles or lunging in draw reins or whatever is really going to help. I’m of the school that you need to train in conditions close to what you’re going to be asking the horse to do ie: similar footing, conditions, etc. I think horses develop different muscles doing dressage than they might in a field. I really have a problem with the “bending at the poll” thing, cranked noses to the chest and mouth pulling I see in the lower levels of dressage. Just too much “on contact”.
So I guess I’m whining that some dressage done by some people is not good for fieldhunters. AND I’m saying some dressage done by some other people is great! Overall I like to say that a potential fieldhunter benefits from good flatwork schooling!!! See?!!!