This is mostly to cut down on keystrokes when preparing soil for planting. I suppose I could use your bundling system and remove a measure of weight instead of a number, though.
I've used a bundling system for arrows for a few years now since I accumulate them quite rapidly and use them as my currency. I've also made bales of leather, fur, nettle, linen and wool, and stack them in one of my various smoke houses I have scattered across the world for when I need to repair/craft clothing, etc. I thought about doing the same with iron, but it didn't seem logical so I usually make wrought iron out of those items or trade them off as is for more portable currency.
I haven't checked out the BAC in quite some time since I've been super busy with RL stuff. It looks like you've done quite a bit with it. As soon as I get some free time, I'll try to incorporate it in with my own mods and see what changes I need to make to my mods for compatibility. With any luck, I'll be able to contribute something more to the BAC.