I totally agree it was sometimes boring but absolutely not because of the weight. It was because of the place it tooks in the inventory (that inconvenient was also reduced when stack had increased). Add an "ammo belt" for ranged units in BG1&2 and there's no more inventory management problem.
Right. The question is, in what form would you like to see the arrow management done? By simply needing arrows and making sure you have them stocked up or by adding weight to those arrows (as inventories do not seem to have slot limitations)? Or another way?