All our fittings are conducted in our State-of-the-Art studios undercover hitting onto a range using ProV1 golf balls.
Fitting indoors you can't determine ball flight and how it is affected by different fitting options. Ball flight and club/swing measurement gets the most accurate readings when it can see the entire flight of the ball. Indoors, even with an optimal setup, many launch monitors have to calculate many of the numbers it reports rather than actually read ball behavior.
Additionally all our locations have access to grass hitting areas and bunkers if needed for wedge testing. Doing this we can test turf interactions where required. This cannot be achieved indoors regardless of the technology used.
Simple, it's much cheaper to have a studio off-course. Also the available locations are limitless.