Not possible with current model. If you flatten as flanges they will collide! You need to think how is this part to be formed.... that's the pressing question …
Agree with Mike,
Part looks like a stamp or a hydra-formed, not bent..
To has your Blank try to use:
If you got bunch of time to make the tryout of your tooling you could use Flatten surface
It depends of your time on the schedulle for your development