EBTax Upgrade from 11.5.10.2 to R12.1.3

HI,

WE are in the process of planning an upgrade to R12 and have performed our first dry run of the upgrade. We are still in our initial stages of getting ready for our CRP1, but i had a few questions related to EBTax.

Here goes

1. It looks like from documentation that an upgraded regime cannot be used as a source regime for a service provider integration! Is this a true statement and has anybody used an upgraded regime to load vertex data into it?

2. We used an R12 data file from Vertex and have successfully loaded data into our initial upgraded instance using the upgraded regime! How do we ensure it worked as expected?