A good rule of thumb with sound boards...
If you are wondering if it makes a difference - the answer, 99% of the time, is YES
Will one swipe with a file in the right place make a difference? Yup
Will tone channel diameter, length, or depth - or any combination or permutation make a difference? Yup
Will barrel length or bore configuration make a difference? Yup
Keg length, back bore configurations, taper angles, lengths, and such make a difference? Yup
Length of cork compared to the cork tang, tightness of cork, composition of the cork? Yup
Flat nose on the sound board tip or comes to a point? Yup
Now, keep in mind, some of the changes are not earth shatterin, and may take a skilled operator to notice... but in the right conditions (aka mixing of all the variables in such a way) a minor change physically can result in a huge change operationally, sound quality wise, or both. There are TONS of "fine lines" in a good duck call... and the vary from one design to another. Finding them and learning to manipulate them based off of your own knowledge and preferences is the part that takes some time.
Experiment and keep notes. Its a tough row to hoe, but worth it in the end.
Wade