I'm using a variety of bags. The adaptation I've made is to install 2 straight pieces of coat hanger wire from the angled post of the rack to the thin bar of the fender. I've put them at slightly different angles and covered both ends on each with black electrical tape.
I don't understand why Magnum leaves such a large gap there or why they make the edging of the rack so thick. Other bike racks cover that area.
Without these wires, my bags touched the spokes. Also, they haven't designed a spot to attach the bottom bag clip as most other bikes have. I'm using the gap, but it's not ideal.
I did try bungee cords ( that's how I got my nickname) to cover the gap, but they ended up coming loose and wrapping around my back gears, which caused my bike to come to a skreeching stop.