I'm thinking about putting a sustainer of some sort into the jem copy I'm currently building. I had the idea, that seeing as I rarely use the single coil pick up in between the humbuckers, why not put it there? so would it work?
That probably won't work too well. The sustainer driver needs to be as near the middle of the string length as possible, so in the neck position. Also there would be loads of interference between the magnetic fields of both the pickups and the driver.