Developing a L2 stack is challenging. It is about balancing the certificabilityand the flexibility.
Certificability means that the stack shall not be altered once it has been TA approved. L2 behaviors shall be black-boxed so the integrators have not to deal with that level of complexitiy.
Flexibilitymeans that stack shall be adaptable to any merchant/acquirer context. The regional nature of the payment is not well addressed by EMVCo specifications:
...
ApplicationSelectionMethod (see entrypoint.h)
KernelSelectionMethod (see entrypoint.h)
emvCallback (see dataxchng.h)
tGetDataCallback (see agnostypes.h)
tBuildDOLCallback (see agnostypes.h)
tStateStateCallback (see agnostypes.h)
AddTag_Contactless (see agnosdatabase.h)
AddUnknownTag_Contactless (see agnosdatabase.h)emvCallback (see dataxchng.h)
