kg matters a lot, of course, but most airplanes are out of space for additional tankage as currently designed. (They are designed for a given mount of fuel capacity volume, in relation to the mass of that fuel volume. None would have a 4x multiple.)

Scaling volumetric storage by a factor of four produces about 2.5x the wetted frontal area (4 ^ (2/3))

If I understand correctly LNG is 20MJ/L so not a 4x difference (but much colder, with all that implies...)

I would agree there’s a likely range reduction, but I don’t have any stats on current normal fueling as a percent of max capacity (iow: are there many routes that are running more than half full today?)