The turbo is still a T03/4B (T34) whatever TurboTechnics want to call it. A T34 with a .55 housing is a downgraded T34 and a T34 with a .48 housing is downgrade further.

All depends what spec turbo the chip was wrote for but I would probably guess it was for the .63 rear end. If so, there will be more safety margin in using a chip for a bigger housing on a car with a smaller housing.

Forgot to mention, a real T35 is actually a diesel turbo for a DAF truck. It wouldn't survive the heat from a petrol engine if used hard.