Hilarious indeed. There is no mystery at all about the ‘Mudchute Omphalos’. Those are just modern features in a local park laid out on the same alignment as the main axis of the Royal Hospital at Greenwich. And that main axis has no esoteric significance. The Queen’s House and later the Royal Hospital were simply laid out on shortest line between the river and the obvious high point to the south, the hill now occupied by the Royal Observatory. The only considerations were aesthetic ones. Also, let’s not forget that the concept of ‘ley lines’ is arguably less than 100 years old.
But actual historical facts about John Dee do have some relevance. Dee and Edward Kelley certainly did claim to have conjured up supernatural entities. They called them ‘angels’ and considered them forces for good. But their contemporaries weren’t so sure.