Apart from sponsorship reasons I dont see why he would stick with Sanwa. In Europe they are really poor. I had one way back (1990) and it gave me nothing but bother. Interference, took notions if it was going to operate at all. Since then I have used my trusty Futaba FF3 (Got it in 91 and still using it - never had any trouble with it and it has never been serviced).
Someone asked about the venue for next year. I was told that the UK are trying to secure the 1:10th euros next year. Now that a Brit is Chairman of EFRA I wonder whether this will be pushed through for definate. I hope it is in Britain. Save me a fortune and I'll know what tires will be working in advance.