I prefer the larger coils on my Excals, lots more coverage with each swing of the coil. I like the WOT coil, it is 15 inches, one of my partners Clyp perfers the Sunray S-12 coil. I think MT Pockets is using the WOT......
I have been told it isn't that hard to go into the Excal controls and rewire it there, but I prefer to splice the coil instead, controls are waterproof, personally I don't want to take the chance of a leak by opening it up.
Pockets does good work and I see he sent you an email, I am sure he can advise you the best way to do it.....