TLs, no, but there's one very good what-if novel (and two crappy ones) about OLYMPIC. The good one is Death is Lighter Than a Feather, by David Westheimer. It's a very good read about OLYMPIC, the attack on Kyushu set for 1 Nov 45. It's good enough that it could be history, and tells from both the American and Japanese points of view, from grunts and airmen, to a battalion commander, REMFs, and civilians.
I did my MA Thesis on both OLYMPIC and CORONET, so if you have any questions, feel free to ask!