Jet-A fuel usually goes in the wings also because it fits there, and the space (not usable for cargo) would otherwise be wasted. It would otherwise need to be i

Jet-A fuel usually goes in the wings also because it fits there, and the space (not usable for cargo) would otherwise be wasted. It would otherwise need to be in tanks between the wings, for the balance reason you note. H2 fuel would not fit in the wings, in any case. LH2 is lighter than Jet-A, but it does weigh, and so still affects balance. LH2 storage does not demand a pressure vessel, but does need insulation. You still want to minimize insulated surface area, so still favor a cylindrical container. So, nacelles slung under the wings seems like the best solution, provided their parasitic drag is not excessive.