I'd wait a few nodes longer, but as long as the roots are strong enough, you can do it. Use an anchor at base of plant in opposite direction of where you bend it. Make a shape first before tying it down.. hold base while you do that, etc etc... reduces stress on roots. tie-down just holds back hydrostatic pressure at that point.
Hello from Russia. You can start training the plant at 3-4 weeks. The earlier you start your training, the better. You can check out my indoor growing diaries to see the training methods. I hope I could help you!