Well, his bulletproofing enchantment on the duster is demonstrably second to at least Ebenezar's work, which protects the head and ankles even if they're not physically covered. Though I'm not sure whether he's actually marking up his robes with spells, or doing it some entirely different way.
I suspect we're going to have to take 'second to none' in a particular context. That is, he's probably second-to-none
in his age and weight category. Of the Wizards who have experience and knowledge and power comparable to Harry, he's among the best at 'magitech'. But I would be
very surprised if he's
literally among the best at it in the whole Council at his age.
Now, in a century or two...
