I can speak to that briefly.
At the end of the day, what extended interswitching does for farmers is give them a competitive option in terms of service delivery. Even when not used directly, the very existence of extended interswitching provides farmers with the ability to hold railways accountable to shipping standards and delivery obligations. It's not necessarily about how often it's used but rather about its very existence, which allows an individual farmer to move away from a monopoly environment to, at least, a duopoly, where there is some degree of competition.