Picasso said that when they talk to each other: "Critics talk about art, but artists talk about where to buy turpentine".
We do end up talking with clients about wood more than we, or they, might expect. I attribute part of that to the prevalence of beliefs in 'magic wood'. These tend to be more strongly rooted in the steel string community, in some respects, or perhaps they just use more kinds of wood, and have ideas about each? There are plenty of Classical players and makers who feel that it comes down to two dichotomies: spruce vs. cedar, and Indian vs. Brazilian rosewood. To the extent that wood makes a difference it's important to hash that out. One issue is that some makers question how much of an effect the wood actually has on the tone, but since tone is subjective, belief tends to become reality.
Another aspect of that is that people tend to use words differently when talking about tone. It can be hard to know what a client means by 'chocolate', and any information you can get can be helpful.
As has been said, for anybody commissioning a guitar, the best thing is to find a maker who produces instruments that you like. Even if you want something other than what you've seen, at least then you have a basis for comparison.
At least some if us have a fairly liberal return policy. Most makers use word or mouth as their main 'advertising'. It's said that; "When somebody buys a thing they like, they tell their friends, but when they buy a thing they don't like, they tell everybody. We can't afford to have somebody out there with an instrument they don't like, no matter what the reason, and it's often easier to simply take it back and give a refund. In the few cases where I've had to do that I've never had a problem selling the instrument later. I'd rather a customer remember me as a poor luthier than a poor luthier and a jerk.