Agree with Triforce, Better for axis if USA messes with Japan by going “island hoping”, Japan don´t really care, establishes itself on the Asia mainland and celebrate with the Germans.
If USA comes close to Japan they will be severly hit, by the fleet and between 4-6 Figs + 1-2 BmB (depending on Japans opening purchase)
USA needs a large fleet to do that, and that means Germany has a lot less to worry about in Europe.
Only time i will hit Japan with USA is if everyone is hiting japan, meaning UK factory in India, USA factory in sinkiang or Alaska, Russia are offensive vs Japan (attacking with the infantry if they survives japans opening turn, supported by the fighters)
But that at the same time of course means Germany is off the hook……
What is best i guess is in the end a matter of taste (but i see most people here tend to go for KGF)