I had the 181 and Givi 30L Dolmiti case on my Brick. I used it for clothes and occasionally groceries—not much additional weight.
When you get the Givi rack, it is
essential that the rack's mounting feet are
flat on the cowl when directly over each hole. My Brick's cowl had factory screw guide tubes molded onto the cowl's interior ceiling; some Brick cowls don't have them. If there is lateral tension on the rack legs because you need to flex them to line up when the rack is installed on the rear cowl, the cowl is likely crack apart at or near one or more holes from the stress, severely damaging the cowl at sometime during travel, especially on gravel roads or pavement with pot holes. That happened to me. The screws should screw smoothly into all the feet with no lateral tension on the rack.
The upside of the destruction of a cowl is there are plenty more out there on eBay to take its place. The paint on the one I found even matched. I wept with joy.
Givi's Monokey is a convenient system on a Brick until the damage happens. I still have the rack and case. This winter, I will attempt to patiently adjust those legs with heat and hammering so there is zero lateral tension on them during bolt up, then I'll road test it. I had a great time with the first experience for a couple hundred miles.
Interested prospective buyers of my Givi case and rack should ping me in summer if I haven't update by then.