I think in a high stress situation you'll grab the first mag that your reloading hand reaches, after the first reload you'll have an empty mag in that most accessible position, so the next time you need to reload, your hand will go again to the same place and grab that mag, that now is empty.
In order to avoid that, you'll need to keep track of what row contains empty mags, and if you're fucked probably won't think that much.
So, I think the gadget will screw you up eventually.
In the old school approach, whenever you empty a mag you drop it in the dropbag, so when reloading, your hand won't find anything in its most accessible position, and will keep searching for the next row, and you'll always get a fresh mag.