Having now arrived home and read my previous post again, I don't think I worded it very well. I don't think that it matters in (ii) that there can only ever be one such rightsholder. I think the result in Cumbrian Newspapers would have been the same if it said "Such of X and Y and Z as shall presently hold more than 10% of the issued shares shall have {whatever} rights". Perhaps all that really matters is that the potential rightsholders are named specifically.
And having now read Cumbrian Newspapers properly, it's much more debatable than I thought. In talking about Bushell v Faith, he says "The article created, in effect, two classes of shareholders - namely, shareholders who were for the time being directors, on the one hand, and shareholders who were not for the time being directors, on the other hand". So you could argue that your right creates, in effect, two classes of shareholders - namely shareholders who for the time being held at least than 25% of the issued shares, on the one hand, and shareholders who for the time being held less than 25% of the shares".