I doubt if many men on this forum have bought more stuff from Chan than I have.
A few thoughts:
I have never had multiple fittings with Chan. My first suit from Chan was a good, well-fitting garment. Subsequent jackets and suits have approximated perfection, once Patrick had a chance to evaluate the fit on my first order. My advice: Don't get more than one suit on your first order. Whether you want multiple fittings is up to you, but it does delay the process considerably. I have never rued not having multiple fittings. By all means wear your best fitting suit to your meeting with Patrick. Chan is a wonderful outfit to deal with. Although their prices have gone up considerably in the past few years, they are still an excellent value. Once they have your pattern "nailed," you can order multiple garments from them, even if you have to travel a considerable distance to meet with them. You will want to.