What it says on the label. An option to limit junk selling to 12 items at a time so that if you realize oops you didn't want to sell that or "wait, how the heck did that end up flagged as junk?"¹ you can still snag it back before it gets buried and you have to resort to an item restoration charge. :-)

(¹ Been there, done that albeit with a different since-broken mod, safely recovered the metaphorical t-shirt.)

Seems like a sensible idea, I will take a look.