If you change lines 69 and 71 to shift - 1, you would be referencing bar 0, the rightmost one that is currently being formed. Is that your intent? If that's the case then shift - 1 should be now, and shift should be b4. If you do this, however, then the opening value of bar 0 (shift - 1) will be used by the ADX indicator. The way I modified it, when bar 0 completes, then the crossing of the ADX lines are by the ADX values of the two most recently completed bars, bar 1 and to its left, bar 2.
