Saddle "fitters" are usually connected to a saddle company or store. With english saddles they do not have the ability to adjust the wool flocking. About all they can tell you is if the horse needs a medium, wide or narrow tree. A lower end saddle with memory foam instead of wool flocking can't be adjusted. If the fitter belongs to the Society of Master Saddlers, then that person is fully qualified.There are very vew in Canada and the US and they will likely be located in the areas where the concentration of upper lever training is greatest.
But I see what you are saying. When I was looking for the fitter last year most indeed are related to certain brand and VERY pushy that it's the only brand to go with to fit the horse perfectly (the reason I eventually went with mine who was very open and suggested several brands to look at from cheaper to expensive).