Some suggestions and theories

[JustAnotherTheory]

But he could be a boy from Madagascar who alone survived the shipwreck of an Arab merchant ship on a deserted island south of Borneo, and while waiting to be rescued found on the beach a large waterproofed trunk full of books and blank parchment that had belonged to John Dee but had accidentally fallen overboard when the good Doctor was crossing the Channel back home from Europe, and had been carried by sea currents down the Atlantic and across the Indian Ocean in a mere fifty years, which made it possible for the boy to kill time by creating a weird book full of bizarre drawings and reports of his erotic dreams in Malgasy but written in a simplified form of the Malayalam script, a book which he brought with him to Europe when he was finally rescued by Malaspina but lost it somewhere in Rome during a visit to Villa Torlonia.

And by a stroke of unimaginable luck, happened to come back with the book to the exact same Nothern Italian/Bohemian region where the parchment was fabricated so that we have no reason to think he was a shipwrecked Indian writing in Malahayam.

(not to mention that he had a magic box full of Taccola, Kyeser and Duc de Berry manuscripts which he copied during his erotic daydreaming)

Yeah, no.