For what it is worth PP changed/updated their integration details on the same day as your post. Might be worth taking a look at. For the store I still have here I have decided to hold off anyway as will have migrated that as well before long.
Had a quick look at the link you dropped and to be honest it all went completely over my head.
I'll just sit back and wait for now, at least another 12 months from now. Then I'll reach back out to Cardinal again and re-verify with them that all my credentials that they provided to me are still relevant and correct and that nothing's changed (or something has changed), then at that stage I'll give it another go.
First customer to try using it with the 3DS gets declined and almost abandons his order altogether - no thanks!