If you leave the carburetor in the stock location and blow through, the pressure would blow the fuel out of the carburetor, hence the need for a pressurized box.
If you mount the carburetor on the turbo you create a potential explosion hazard because the turbo and all the plumbing has a combustible pressurized mixture.
Other than that, it's just jetting.
The carburetor wasn't designed for anything other than non-pressurized running, so modifications have to be made to make it work.
On the other hand, I put a turbo on an Opel Kadett (yeah, a long time ago) with a draw through 38MM Mikuni carburetor. No waste gate. I had minimal tuning problems and put 50,000 miles on it with zero problems before I sold it. The only thing of note was the visible wear on the carburetor inlet from the air flow.