The answer depends on how risk-averse you are.
The problem is to identify the arrangement that maximizes the minimum share of the society’s resources. An unequal distribution of wealth would be to everyone’s advantage if the least advantaged person in the distribution were better off than the least advantaged person in any other possible distribution.
In the case of a benefit to the least well off that requires a sacrifice by those in the middle, a risk-averse person behind the veil of ignorance would choose the benefit on the grounds that he or she might end up being the worst off on the other side of the veil. But a less risk-averse person might figure that the chances of winding up at the bottom are low, and decide that withholding the benefit was a reasonable gamble.
Depending on your assumptions about the psychology of those in the original position, that is, you get different answers to the question of how much inequality is tolerable and what kind of basic structure should be endorsed.
For example, what about an economic system that permits those at the top to have much greater wealth than those at the bottom, but that also, because it creates more jobs, reduces the number of people at the bottom? How should we decide between maximizing the share of those at the bottom, and making it less likely that anyone will hit bottom?
As for my personal preference, I favor maximizing the share of those at the bottom over minimizing the number of those at the bottom. The latter is compatible with a society in which someone could starve to death through no fault of their own without anyone trying to do anything at all about it, and that’s obviously unacceptable.
I’m not at all certain, though, that redistributionist policies by themselves are the ideal way to maximize the share of those at the bottom. More likely, it’s some combination of a competitive market society with a “safety net” and stable civic institutions, families, neighborhoods, schools, etc. Something like what Rawls called a “property-owning democracy.”
Below, the veil of ignorance.