This would make a pie a little more like a tracker, allowing new money to be invested according to current actual stock weights rather than the initial weight.
E.g. 4 stock pie, initially each at 25%. Over time, A doubles, D halves, B & C are unchanged. Automatically weighting to current, would set the weights to, A 44.5%, B & C 22.2%, D 11.1%.
This could be done as a pie setting, so pie weights are continually adjusted (useful for auto reinvesting) or as a ‘reweight’ button on the edit pie.
As a part of this, on the holdings, edit pie weighting’s screen, show the current weight somewhere.