What if the AABB use float3(0,0,0) and float3(1,1,1)?

In the code,AABB box use texcoord of float3(0,0,0) and float3(1,1,1).Why this?
As I know, NDC in unity is  float3(0,0,0) and float3(1,1,1). Why didn't you use this?
If use this, what will change to the code?
I tryed to do this, but failed. Would you like make another script for this ?

