Do not attempt to make this product via the one-hit cavity punch/die method that you described in your initial post. Due to material springback, the bends will not come out at 90 degrees. It takes some special tricks to get 90 degree bends using a wipe die (a die that "wipes" the flanges up), and I think they may be difficult to pull off if you are wiping all 4 sides at once (as opposed to one or two opposite sides). You will also need to incorporate some sort of spring or urethane stripper system to be able to remove the parts easily from the cavity if you go that way... Otherwise, the parts will likely stay in the cavity and you'll have to pry them out! Yes, this part can be made in this fashion, but unless you are making many thousand pieces it is not worth the effort to build a die which is robust enough to make this work properly.
An easier way to accomplish this part would be to use V press brake dies... You would need a small <1" segment of a male punch, and the female die could be that length or longer. Be sure the punch is a gooseneck type (otherwise a flange may collide with the ram when you make your second bend), and be sure the die is narrow (.375" V opening or so) to allow you to gauge the .5" bend using a manual gauge. You can clamp a little stop block to the back of the die to act as a gauge for the .5" bends. Obviously you are not going to buy a press brake to make this little part, but I have seen little manual benchtop mini brakes sold by harborfreight or grizzly that would fit the bill. You may even be able to modify an arbor press to hold the press brake tooling to do the job.