For grocery getting and everyday utility riding I prefer a bike that can carry a full set of panniers in back and at least one small grocery bag or a change of clothes and a lunch up front. Having the option of throwing extra items on a front cargo/porteur rack is one of the handiest features a utility bike can have. Plus, most bikes will tend to ride better with a balanced load.
People talk about the need for low trail geometry for carrying loads on the front fork, and perhaps for touring or randonneurring that’s true, but I haven’t found it necessary for utility riding. Much more important is a good center stand that lifts the rear wheel off the ground so the front wheel stays planted when the load is distributed between the front and rear racks. A centering spring or strap to hold the wheel straight during loading helps as well. When we’re talking about short trips to the store or library, ease of loading and overall carrying capacity are much more important than light steering that mitigates for fatigue over a long day in the saddle.
So, if you’ve considered a porteur/cargo rack for your grocery getter, but you’ve hesitated because your bike’s geometry isn’t optimized for carrying a front load, I’d encourage you to give it a try; personally I feel it’s a non-issue for the typically short distances most people travel for grocery shopping and errands. More important is a set-up that’s optimized for the loading process with a good, double-legged centerstand and a front wheel stabilizer. Once the bike is loaded and rolling, you’ll quickly adapt to the steering and you’ll be glad for the extra carrying capacity.