The hook might have been very useful to carry string tied packages a few decades ago, but I do not receive many of those anymore. I do carry heavy plastic bags occasionally, but the hook is too small to grab them. I've discovered if you carry a flat carabiner (like this Niteize #4 locking biner), you can use it to carry a few bags, and grab the carabiner with the hook.
I normally EDC an alox SAK without the hook. As a work-around, I've found if you simply loop plastic bag handles over the study alox body, you can carry quite a few heavy bags like this.
I think you might pop a scale off a cellidor model if the bags are heavy, so I would not do this with the 91mm's.