I don't know about the "literary" way, but it seems to be largely a UK/US issue, as you suggest. In fact it is probably a US/us issue, "us" being the Brits and ex-colonials. Interestingly, my beloved Chambers gives it as "EE" and also (my emphasis) in the US as "AY". So maybe it is a regional thing in the US. By the way, I tried the spell checker for the first time and enjoyed "excommunicate" for ex-colonials! Although a little pointed, I venture to suggest!
Rgds, lusy