It would certainly be open to the user to argue before a court that as the plain English version was more easily understood and avoided obscure legal terms, the

It would certainly be open to the user to argue before a court that as the plain English version was more easily understood and avoided obscure legal terms, then that is the version that is enforceable against them. This is particularly the case in the EU where legislation requires consumer-facing agreements to be in language that users are able to understand. As far as I'm aware the issue has not been directly tested before a court. In part because the two-tiered approach is not adopted by many companies, and also because disputes over company's terms rarely reach court. It would definitely be interesting to see a court's take on the two-tiered approach though. Speaking of plain English terms, at my workplace I recently re-drafted our main consumer-facing agreement to use exclusively plain English. This is likely to mean we would be more likely to enforce it, and also, I don't feel any certainty has been lost or if there has been any reduction this is outweighed by the benefit in making the terms more digestible by users.