How to make a reverse bend in a sheet metal box
Unless you have a brake that has fingers or the clamping bar has removable plates you are still going to have a problem folding the third fold of the other three. 

If you are able to do normal four sided box folds then for the reverse flap you would have the option to make a normal box and then attach a separate plate to one side to create the riser flap. This could be attached with welding, spot welding, rivets or sheet metal screws.