Talk about going round in circles... as we've discussed at length many times before, the new carriers have a built-in capability for catapult installation so there's no question that the capability can simply be added for the appropriate fee. The point is that the capability was mentioned supposedly a mere "luxury add-on" although many of us suspected it probably had something to do with the possible purchase of Hawkeyes somewhere down the line. But as time has progressed, it's become clear that it probably has more to do with a latent desite to utilise Typhoons rather that F35's.
I don't know what the notion of Britain building an F35 is all about - if we want an F35 fleet then we'll get one, and all the nonsense about sharing technology will be forgotten as it always has been since the 1950's. The problem is cost, especially when weighed against the almost inevitable purchase of more Typhoons which (unless there's a change in the order of battle) will be redundant. Even a monkey can work-out what the obvious solution is...