Shauna's ascent is amazing. Gav is obviously trolling.
Reluctant as I am to continue this sorry 'debate'.
Then, as should always be the case, you give it an E grade, consistent with how hard it would be to do other trad routes in an equivalent style.
That's not what anyone has ever done though, because it's not useful info. Generally people want to know two things - how hard is the boulder problem, and how hard is the scary bit. E4 7a for West Side gives you this. Upgrading it because 7a is dead hard is pointless, we already have that information. If you do the 7a bit, you then have to do an E4 bit to get the tick - it's 6a move at 4m, which is why it's the same grade as The Knock, which is a slightly easier move slightly higher, although in that case it's only 6a to get there. The same logic applies to the other examples, and is the reason why Verandah buttress is still HVD despite a greater tech/trad discrepancy than West side.
(At Slipstones they did get a bit carried away or confused admittedly, and as you go right along the crag the trad grades become superfluous. But it's an old guide now, and an isolated example.
Honestly beggars belief why people philosophise about how they think grades should work, and then go back to complain about how they are wrong, rather than just looking at the given grade and applying some common sense to why it might have been given.