I tend to J2 (never J1, IMO too much advantage in holding off a round) and have started putting a few units in the Carolines on J1. At worst it doesn’t change anything, at best it gives a few strike opportunities. Unless your plan is a very early (J4) India capture, it’s a good move.
I have been starting with a BB, loaded carrier, sub, dd there and sometimes a transport as well. The merits of Japan taking the inf off Carolines to use in attacking other islands are worth discussion, since they’re the only Japanese land units in the starting setup that typically don’t get used offensively. Even the Paulau inf gets used for Celebes often, and the inf in Iwo Jima can be utilized without going out of your way too much.
