The prius gen3 inverter has been successfully liberated with an open-source logic board. Follow this @openinverter.org. This inverter is about 3x the size of the Smart inverter so where will it fit in the Smart car? One user put it inside the battery box and some of his battery cells ended up on the back floor. I am dismantling a Smart inverter to see if a logic board will run it sucessfully. It does not come apart easily and I'm machining my way into it without doing damage. But right now the quickest route is the gen3 inverter and whatever 200vdc or more battery bank you can fit into the car. The idea here is to use the stock motor/diff unit thus saving all kinds of extra and unnecessary, IMHO, work.
To specifically answer the OP's question, no you do not go that route as the Bosch AC 3-phase motor simply needs an inverter to run it, not an expensive 'controller'. A (~$400-) junkyard prius gen3 inverter will work fine and provide all the other services too such as 12vdc charging (dc-dc converter) and high voltage battery charging (360vdc). All you need to do to the prius inverter is to replace the logic board with an open-software logic board that you control, not Daimler Inc. Then you can use any battery bank (200 > 360vdc) to run the car. See YouTube and <openinverter.org> for parts sourcing. This is the cheapest and easiest route to press all these 'bricked' SmartED3 cars back into service. No need to replace motor/diff or any suspension; to do so is simply a waste of money and effort since the stock ED3 is in so many ways perfection of a concept.