What’s required to make an N/A carb work on say a 671 blower?

If the car is street driven and any semblance of fuel economy is desired then boost referencing the power valve circuit is really the only right way to do it. Plugging the PV can work but to make the engine happy at wot the mains are so rich that cruise economy suffers badly. Boost referencing the PV gives you a whole new circuit to tune the fuel delivery. It keeps the mains in check when you’re not in positive pressure.