The pattern was generated by Fuji Flexa optimizer. Actually it do not care to follow logical pattern (back and forth) because the length of travel is the same overall.
Who knows what the japanese were thinking, but there are 3 reasons I think 1. Flexa does not "know" that there is pattern, it just starts from a point and follows some complicated algorithm 2. Its better to start from centre, because this gives less stress to edge components (centre may flex a bit under placing pressure). But you have to support centre anyway and perhaps this is a minor problem 3. "A bit random" pattern does not generate harmonic vibrations.
