I can’t think of any reason to build a NB on Line Is. Even if you plan to bounce to the Atlantic it would be just as well to depart from San Fran sz10 where you already have a NB (both are 3 spaces to sz89). As the US you are looking for forward bases to operate in the Pacific, not working backwards? You need to interfere w/Japan in the South Pacific (Money Islands), and Line Is doesn’t get you anywhere near there. Plus Line isn’t a good place to set-up to defend against a more powerful Japan if you go heavy Europe either.
Better to stage off the coast of Queensland, or to have the US take the Caroline’s (both have AB/NB), and the Anz can reinforce w/support ships and ftrs to scramble. Once you establish a good defensive posture you can start adding in subs/bmrs and go offense. Make the Japanese block you out feeding you destroyers that you take out with subs/air power. At some point hit hard w/USA, and have Anz clean up the Japanese Capital ships. You could also set up the Pac allies in a good defensive position and entice the Japanese to hit you, then clean up. Once Japan starts loosing big chucks of the Imperial Navy they fold up like a cheap suit.