Yoga can absolutely help. I've been doing (the easy yoga) for a few years now.

Not only does the stretching help, it helps with balance and overall pain reduction. And either before or after, I try to practice some mindfulness meditation for a few minutes.

With CRPS, gotta hit it with everything including the kitchen sink. And that means that along with conventional western medicine, you need to consider experimenting with any kind of complementary therapies that can help. And yoga is definitely one of them!