Why Wait 
Start slowly and increase your traing and you should be fine 
I just thought it might affect his hunting
Well, I am no expert and there are plenty around here, but I don't think it will hurt your hunting. I may be wrong, but thats just my opion.
Are you doing the FF training your self?
Have you trained FF before?
If you are just going by what you have read on how to FF, I would seek an expert for advise and dirrection. I worked with a trainer who worked with me on FF my dog. They are not the best dogs in the field, but they are mine and do as I wish (most of the time
) and I am happy with there ability.
Can my dogs learn more, Yes. Are they exceptable to many other hunters or field trial trainers, No.but there my dogs and do fine for me and what I use them for.
I have even see highly trained by the best trainers get snuffed by there dogs
