I'm far from the turbo expert, but I'll try to help. I hope we're on the same page, because twincharging to me means using two smaller turbos on a motor instead of one larger one. The advantage would be a faster spool-up of the rotating assembly and quicker response to your instructions via your right foot.

Current thinking is to use two turbos on a blow-through installation, where you use a modified Holley carb with an aluminum diecast bonnet at the carb inlet and blow dry air into the carb.