Changing the original poster's proposal a lot, what if Leyte Gulf had resulted in heavy Japanese losses, but also heavy USN losses? I have this idea roaming around in my head of adding in a clash between Kurita's force and one of the US battlelines, with lost battleships on both sides. Heavier losses to Japanese land-based air as well.
(Note: this idea of mine is one that even I have trouble in believing it would work)
The USN takes a breather after this battle. Still victorious, but time is needed for reorganization and evaluation. The IJN meanwhile, they lost, but with the damage inflicted on the USN, the IJN's honor is intact.
Going on from that, the US commanders in the Pacific are more inclined to accept the Japanese surrender proposal as the original poster mentions. The IJN, facing the reality of the situation, backs the idea of a surrender. Even to the point of fighting with the army over it.
Just a crazy idea of mine. My apologies to the original poster if I mangled his idea.
dilvish