1. One things get this close, I'd like to see some test results first. I am a bit mathematically challenged so I don't see the immediate difference. If however you get results better or worse than with using the SMA, then we have a basis to build further hypotheses on.
2. If the whatever-MA mimics the SMA, why bother with whatever-MA's?
3. Actually XDEV does not use the SMA. It uses the mid-points between daily high and low. And that is how it should be. Would you use the same price for calculating the whatever-MA?