"This would be 45 NM in direction 327 degrees from the last known position of MH370 reported by FR24, indicating some kind of flying ability"
Not so - at Lockerbie debris was scattered for mile forward of the point the plane came apart - - 7 miles and high and several hundred knots means the parabola of bits can be pretty significant.
In fact, in the absence of any other info you can calculate where breakup occurred by logging the different remnants and their size back along the debris trail