One point he missed. Market (and pricing) differentiation was only half the reason for the '424 / '050 split. The other reason is that '050 is much less lipid-soluble, tending to keep it away from marrow. The in-marrow effects are most of the point of Jakafi, but are pure side-effect for baricitinib. So there are real safety/tolerability issues in the distinction.
There's a paradoxical element, although not in a big market. Lipid solubility is needed to make a drug topically effective, so even though bari is a better try as an oral agent against psoriasis, ruxo is a better try as an ointment.