It is in fact irrelevant, provided the effort spent on managing inventory is more or less the same.
I say this since the amount of work to be done by the user has to be taken into account – relative to other software, since efficiency in managing Inventory could make or break a business.
I agree with @eko that Dynamic Recalculations are the better option.
I remember the case that lead to this development and it was about the inability to account for cost when there’s insufficient quantities.
Personally, I would have settled for a searchable flag of the culprit transaction and a contextual button to rerun the calculation for that particular transaction once the quantity has been fixed by the user but I’m not in a position to judge the feasiblity of such development. However, I can only hope that the developer provides a solution that ultimately checks all the boxes.