Reminds me of some WoW addons. I remember one that would combine all your bag/inventory space into a single grid visually (I really didn't like that when I tried that, myself, but it was very different). And there would be others that, yes, would functionally sort items by bag under your configuration control, as in the OP. Of course WoW also had special bags for professions (and Warlock soul shards, long ago) that could only carry those mats/tools, with more slots available for less cost.
One thing I never saw was a top/bottom sorting system, which would effectively double the available sorting categories - i.e. one set of items sort into the bag from the top down, and another set from the bottom up, with both growing towards the unused space in the middle (like a heap/stack memory model). Would have liked that...
In Eldevin, I use various bags for various purposes. I many cases I just accept whatever the autosort does, and live with it.