The first one I've already mentally explored, funnily enough.
I'm a sad act and no mistake.
Where it is indeed true that the distribution of hydrogen throughout the universe is thought to be asymmetrical this, in itself, doesn't make a difference as to the mass required to hit 'critical mass' (that is a constant and a function of atomic weight, nuclear force, weak and strong electromagnetic nuclear forces and Boyle's law).
If the propagation of hydrogen is discrepant, that would only make a difference as to how
long the required mass of hydrogen took to reach critical levels - not the amount required to do so.
I really need a hobby.