There is a tale in one of the Norton history books that the pilot was wriggling to got onto (into ?) this kneeler at one of its showings, and an onlooker was heard to say "this Norton really is unapproachable !".
Any advantages its lower form had were apparently negated by the pilot having to strain his neck to see, and having less feel for being in control. They were banned somewhere not long after it was shown ?