My point was Phil’s domains are so valuable, they really “should” (not trying to tell him what to do) be held directly with Nominet. Think of it as an insurance policy.
My advice would be the same for anyone with a valuable OR extensive portfolio. If you have just 10 domains but they’re stellar A++ grade then join Nominet! The consequences of losing even one of them will be hundreds of times more expensive than the Nominet fee. And you’ll pay more than the initial Nominet fee if you end up having to rope in a decent lawyer for an hour or two to get you out of a pickle.
And of course if you have 100+ domains at any quality level, join Nominet. After the first year that will add just £1+VAT or less overhead per name, plus you’re completely protected and in control.
I don’t see why anyone is still using a registrar in 2018, unless you have a very small number of poor quality names. After all, unlike ICANN and the .com world, Nominet make it both cheap and easy to go direct...
Sure, there are better registrars and worse registrars (and VERY bad registrars) but none will give you the simple, straightforward, reliable experience of working immediately with Nominet. And how could they? You’re still beholden to Nominet ultimately if you go via a registrar, but it’s just another level of complexity and another opportunity for something to go wrong.