I would like the option to drop magazines when reloading instead of putting them back in your inventory for example if there are only 5 bullets left.
After a lot of reloading it can be quite surprising when you read the HUD saying you have 5 magazines left but then you reload and get a magazine with only 3 bullets and in total only have like 15 bullets left because all of your magazines are nearly empty.
Unless the current HUD changes to display unused magazines and used magazines separately this will probably remain an issue for some players like me.
Realistically I think a person either would keep track of his used and unused magazines better or simply not put used ones straight back in his pockets.