[Mithadan]

It is likely that a universe where Planck's Constant is slightly different would be very... uncomfortable for those traversing your hypothetical wormhole.

As an aside, an old friend of mine is firmly convinced that all of the changes mentioned in Morgoth's Ring were, in fact, what Tolkien intended. In other words, Ea was always round, Orcs were not corrupted Elves, etc. If asked, he would expound upon how the mythologies would have been revised to accommodate these changes.

I do not recall how my friend came down on the "transmission" methodology that Tolkien would ultimately have settled upon. In my view, Tolkien himself never decided. If you look, one can find hints that JRRT had never even completely rejected the Aelfwine/Pengoloth idea